Special Announcement
Introducing our New World's Healthiest Foods Menu! You can get 100% of nutrients from the WHFoods.
Special Announcement
Introducing our New World's Healthiest Foods Menu! You can get 100% of nutrients from the WHFoods.
Atherosclerosis is the build-up of fatty deposits in the walls of the arteries. When these deposits, or plaques, build up in the blood vessels of the heart, they cause coronary artery disease, which can lead to a heart attack. When they build up in the blood vessels of the brain, they cause cerebral artery disease, which can lead to a stroke. Atherosclerosis is the main underlying cause of heart disease. It progresses slowly and in some cases begins development from as early as childhood.
Heart disease affects 60 million Americans and is the leading cause of death of adults in the United States. An estimated 1,100,000 new or recurrent heart attacks occur annually which translates into someone experiencing a heart attack every 20 seconds; one-third of these episodes will lead to death.
Although genetic inheritance and family history plays a role in the development of atherosclerosis, lifestyle and healthy food choices are being found to have equal, if not greater, impact on arterial health.
In this landmark study, the effects of consuming a diet high in vegetables, fruits, soy foods and nuts were compared to either a control diet that was very low in saturated fat and based on milled whole-wheat cereals and low-fat dairy foods or the same diet plus the statin drug, lovastatin. Study participants, a group of 46 adults (25 men and 21 postmenopausal women with high cholesterol whose average age was 59) were randomly assigned to follow one of these three diets for one month. At the end of the month, all three groups showed a decrease in LDL cholesterol and C-reactive protein.
In those on the control diet, LDL dropped an average of 8%, and C-reactive protein dropped an average of 10%.
In those on the whole foods diet, LDL dropped an average of 28.6%, and C-reactive protein dropped an average of 28.2%.
In those on the control diet plus lovastatin, LDL dropped an average of 30.9%, and C-reactive protein dropped an average of 33.3%.
A second study on the portfolio diet involving many of the same researchers was published in the March 2006 issue of the American Journal of Clinical Nutrition.
This year-long study, which followed 55 volunteers with high cholesterol levels, showed that a diet that includes a combination of cholesterol-lowering foods, such as soy, plant sterols, almonds and viscous fibers, can reduce LDL-cholesterol levels by 20% or even more. Subjects ate a diet that, for every 1,000 calories, included one gram of plant sterols, 10 grams of viscous fiber, 22.5 grams of soy protein, and 23 grams of whole almonds.
Enriched margarines were used as the source of plant sterols (since these contain hydrogenated fats, we recommend whole food sources of plant sterols listed below under Beneficial Nutrients for Atherosclerosis & Their Best Food Sources / Phytosterols), the fiber came from oats, barley, okra and eggplant, and the soy proteins came from soy milk and tofu. Participants were also instructed to eat five to ten daily servings of fruit and vegetables.
Regular blood tests during the year allowed the researchers to measure total cholesterol, triglycerides and HDL cholesterol levels. LDL levels were calculated from these results.
Average cholesterol reductions at 3 months and 1 year were 14% and 12.8, respectively—less than those observed after treatment with statins; however, 31.8% of study participants had reductions of LDL-cholesterol of more than 20% at 1 year, which is similar to results from statin therapy and equivalent to a 30% reduction in risk of death from heart disease.
HDL-cholesterol levels were also increased, and a small but significant 13% reduction in blood levels of triglycerides was noted. The researchers also reported a "small but statistically significant" loss of weight among the participants.
Those who best followed the dietary recommendations experienced the largest drops in LDL-cholesterol levels. Participants found it easiest to incorporate the almonds and plant-sterol margarine into their daily lives with 79% and 67% of volunteers, respectively, reaching the targets for their intake. Fiber and soy protein were more challenging since neither are found in most fast foods, so they require a little grocery list planning; their targets were reached a bit less, by 55% and 51%, respectively.
More than 30% of motivated participants who ate the dietary portfolio of cholesterol-lowering foods under real-world conditions were able to lower their LDL-cholesterol concentrations more than 20%, which was not significantly different from their response to a first-generation statin. "The study's findings suggest that the average person can do a lot to improve their health through diet," said lead researcher David Jenkins.
The CARDIO2000 study, another epidemiological study whose results were presented at the August 2003 meeting of the European Society of Cardiology, suggests that while eating 5 or more servings of fruits and vegetables a day provides more significant benefit—a 72% reduction in cardiovascular disease risk—that even moderate consumption of fruits and vegetables (2-3 servings per day) is associated with a much lower risk of heart attack. Lead researcher, Dr. Demosthenes Panagiotakos from the University of Athens, Greece, noted that each serving of fruit, up to 2.5 servings each day, conferred a 10% additional reduction in coronary risk, while each serving of vegetables, again up to 2.5 servings, provided an additional 19% reduction in risk for coronary disease.
The unique importance of fruits and vegetables also jumped for researchers at the Population Health Research Institute in the School of Medicine at McMaster University in Ontario, Canada. These researchers studied dietary information from16,407 participants from 52 countries in order to determine the relationship between diet and the risk of a sudden heart attack (acute myocardial infarct, or AMI). Amongst all lifestyle factors - including smoking and exercise - diet accounted for about 30% of all modifiable risk when it came to the threat of a sudden heart attack, and within the diet, it was green leafy vegetables, raw vegetables, cooked vegetables, and fresh fruits that stood out as the most potent protectors against AMI.
In just 3 months, eating a Mediterranean-style diet can reduce risk of heart disease by 15%—almost twice as much cardiovascular risk reduction as that seen on a low-fat diet—shows the Mediterranean Diet, Cardiovascular Risks and Gene Polymorphisms (Medi-RIVAGE) study.
Published in the November 2005 issue of the American Journal of Clinical Nutrition, this is the latest in a string of studies to affirm the benefits of this healthy way of eating.
French researchers assigned 212 men and women at moderate risk for heart disease to either a Mediterranean diet or a low-fat diet for 3 months.
Mediterranean diet participants were instructed to base their meals around whole grains, fruits, vegetables, nuts, and olive oil, and to eat fish 4 times a week, but red meat only once a week.
Those on the low-fat diet were told to eat poultry rather than beef, pork and other mammal meats, to eat fish 2-3 times a week, to stay away from animal products high in saturated fat, and to eat fruit, vegetables, low-fat dairy products and vegetable oils.
Among those on the Mediterranean diet, total cholesterol dropped by 7.5% compared to 4.5% in the low-fat diet group.
Overall cardiovascular disease risk fell 15% on the Mediterranean diet compared to 9% on the low-fat diet.
The Medi-RIVAGE study suggests that the healthy fats found in a Mediterranean-style diet—such as the healthy way of eating espoused at the World's Healthiest Foods—not only do not promote heart disease, but lower cardiovascular disease risk. And these fats—the monounsaturated fats in olive oil, omega 3 fats in fish, and mono- and polyunsaturated fats in nuts—not only lower your risk of heart disease but greatly improve the flavor and taste of your food while also increasing satiety (feeling satisfied after eating, so you are much less likely to eat more than you need).
A study published in the November 2006 issue of the Annals of Nutritional Metabolism provides new understanding of the ways in which a Mediterranean helps prevent cardiovascular disease.
In this study, 8 healthy men were given either a 1,000 calorie Mediterannean-like meal in which olive oil was the primary source of fat or a 1,000 calorie Western-like meal in which the fat was supplied by meat.
After consuming the Mediterranean-like meal rich in vegetables and olive oil, a significant increase was seen in the activity of serum paraxonase (PON 1), an enzyme transported on HDL in the blood. PON1 protects cholesterol from oxidation and inhibits
macrophage foam cell formation—two initiating steps in the development of atherosclerosis. Also, after the Mediterranean-like meal, the men's blood levels of carotenoids, which also function as protective antioxidants, increased a whopping 74%! In combination with these defensive benefits, the men's blood levels of pro-inflammatory C-reactive protein dropped 6% for a period of 2 hours after the meal. None of these beneficial effects were seen after the men ate the Western-style meal.
A review of existing studies—both epidemiological (population) studies like the Lyon Diet Heart Study and the GISSI trial, and randomized dietary trials—has confirmed that adherence to a Mediterranean diet may play a significant role in preventing coronary heart disease (CHD) (de Lorgeril M, Salen P., Public Health Nutr).
The review suggests that current research indicates this may be due, in part, to the fats found - and not found - in abundance in the Mediterranean diet.
The traditional Mediterranean diet is rich heart-protective fats including oleic acid, a monounsaturated fat found in olive oil, and alpha linoleic acid (ALA), an omega-3 fat found in plant foods, especially flaxseeds and walnuts. In addition, the Mediterranean diet is low in saturated fats, which are thought to increase levels of LDL (bad) cholesterol, and in omega-6 fats, which are pro-inflammatory.
Results of the Lyon Diet Heart Study found that patients with CHD who followed a Mediterranean diet, which is naturall rich in ALA, had a 50-70% reduction in the risk of heart attack after 4 years of follow up.
In the GISSI trial, patients following a Mediterranean-style diet, who also received supplementation (approximately 1 gram per day) with the omega-3 fats found in cold water fish, EPA and DHA, reduced their risk of cardiac death by 30% and their risk of sudden cardiac death by 45%.
The authors of the GISSI trial point out that in persons following a Mediterranean diet, intake of the anti-inflammatory omega-3 fat, ALA, will average about 0.6 to 1% of the total daily energy intake (approximately 2 grams per day), while the average intake of pro-inflammatory omega-6 fat (linoleic acid) will not exceed 7 grams per day. To put this in perspective, this gives a ratio of omega-3 to omega-6 of at least 2:7, even without taking into account the fact that cold water fish, which also supply omega-3 fats in the form of DHA and EPA, are also commonly included in a Mediterranean-style diet. In the typical Western diet, the ratio of omega-3:omega-6 fats is a highly pro-inflammatory 1:20.
The review concludes that a Mediterranean diet that includes even small doses of omega-3 fatty acids—approximately 1 gram per day of EPA + DHA (which are concentrated in cold-water fish such as salmon, sardines and tuna) or 2 grams per day of alpha-linolenic acid (which is most concentrated in flaxseeds, followed by walnuts and then canola oil) may be very protective. Bottomline: enjoying a Mediterranean-style diet that includes flaxseed, walnuts and cold-water fish may significantly lower your risk of cardiovascular disease.
New results from PREDIMED, a long-term multicenter trial supported by the Spanish Health Ministry to assess a Mediterranean-style diet's effects on cardiovascular disease prevention, show a traditional Mediterranean diet (TMD) decreases oxidative damage to LDL cholesterol and protects against coronary heart disease. PREDIMED researchers randomly assigned 372 subjects at high cardiovascular risk to a low-fat diet or one of 2 TMDs, a TMD plus virgin olive oil or a TMD plus nuts, in a 3 month, controlled, parallel-group trial.
Consumption of the olive oil TMD reduced levels of oxidized LDL by 10.6 units per liter, while the nut-rich TMD reduced LDL oxidation 7.3 units per liter, but no changes were seen in the low-fat diet group. The TMD plus nuts also led to a healthy reduction in triglyceride level and an increase in HDL ("good") cholesterol levels. Both TMDs decreased systolic and diastolic blood pressure as well. Given these results, "It's easy to foresee that the participants who follow the Mediterranean diet supplemented with olive oil or with nuts will show in the long run a 50% reduction in the incidence of cardiovascular complications," said Barcelona, Spain, PREDIMED researcher Dr. Ramon Estruch.Arch Intern Med. 2007 Jun 11;167(11):1195-203.
Researchers at Kaiser Permanente in Vacaville, CA and the F. Edward Hebert School of Medicine, Uniformed Services University of the Health Sciences in Bethesda, MD analyzed the effectiveness of the Mediterranean Diet in preventing cardiovascular disease by comparing it to three other very popular diets: (1) very low carbohydrate (as represented by the Atkins Diet); (2) low carbohydrate (as represented by the Zone Diet and the South Beach Diet; and (3) very low fat (as represented by the Ornish Diet). After analyzing the results of approximately 40 studies and evaluating study results and study quality, they determined that the Mediterranean Diet was the only approaches that showed consistent success in preventing cardiovascular disease. Among all of the diets rated, only the Mediterranean Diet received a rating of "A" with respect to its heart-protective qualities.
The Mediterranean diet, already shown to help prevent the development of cardiovascular disease, can help people with established heart disease, either preventing or lessening the severity of a heart attack, shows a population-based study from Greece published in the journal Nutrition (July-August 2006).
The article reports the results of the Greek Study of Acute Coronary Syndrome (GREECS) of 2172 patients (76% men, 24% women) who had been hospitalized with a heart attack or unstable angina.
Their adherence to a Mediterranean diet was assessed by a 156-item food frequency questionnaire and correlated to a Mediterranean diet using a 55-point scale: the higher the score, the closer to a Mediterranean diet.
A higher Mediterranean diet score was linked to lower levels of several biological markers of heart disease and a lower risk of another heart attack.
"A five-unit increase in diet score was associated with 15% lower odds of having a heart attack," said lead author Demosthenes Panagiotakos from Harokopio University in Athens.
Lower adherence to the Mediterranean diet, which was found to be higher in younger patients, smokers, and people with a family history of coronary heart disease (CHD), was associated with a more severe CHD.
Why is the Mediterranean diet protective? This healthy way of eating promotes improvements in blood pressure, body weight, blood lipid concentrations, and inflammation—all mechanisms that protect heart health.
"These mechanisms might have a major impact on plaque instability, rupture, or erosion and the exacerbation (severity) of the following acute MI (heart attack)," wrote Panagiotakos.
In addition to helping your heart stay in good shape, another study led by Panagiotakos indicates that a Mediterranean diet can help you love the shape you're in.
In this study, Panagiotakos analyzed the foods consumed during a normal week by 1514 men (18 to 87 y old) and 1528 women (18 to 89 y old) participating in the ATTICA study. Even after controlling for age, sex, physical activity status, metabolism, and other variables, those most closely following a Mediterranean diet were 51% less likely to be obese and 59% less likely to have central obesity (the apple body shape, which has been linked to increased risk of metabolic syndrome and type 2 diabetes), compared to those not following a Mediterranean diet.
Additional studies confirming that what you eat can have a tremendous impact on your risk for cardiovascular disease were published in September 2004. The first, which appeared in the American Journal of Clinical Nutrition, evaluated 455 women participating in the Coronary Risk Factors for Atherosclerosis in Women (CORA) Study and found that those whose dietary pattern was characterized by high intakes of meat, margarine, poultry and sauce, and low intakes of vegetarian dishes, wine, vegetables and whole-grain cereals had a 1,230% higher risk for coronary artery disease compared to women following the opposite dietary pattern!
The second, called the INTERHEART Study, involved 52 countries representing every inhabited continent and more than 30,000 subjects, and was published in the Lancet. Its finding was that nine risk factors, all of which are modifiable through diet and lifestyle, account for 90% of all heart disease in men and 94% in women—regardless of race or the country in which they live.
The nine factors affecting risk are:
The most dangerous type of LDL is identified by a test that measures the amount of its carrier protein, which is called apolioprotein B or ApoB, that is present in the blood and contrasts this with the amount of the carrier protein for the larger, less dangerous LDL, which is called ApoA1. The resulting ratio of ApoB/ApoA1 is a much better indicator of risk than a simple total cholesterol level.
Persons with a high ratio of ApoB/ApoA1 have a 3.25 or more than 3 times higher risk of heart attack compared to those whose ratio is low.
Another recent study to support a link between a diet high in fruits and vegetables and a reduced risk of heart attack or stroke appeared in the November 2004 issue of the Journal of the National Cancer Institute.
A team of researchers including Dr. Walter Willett, the highly respected epidemiologist at the Harvard School of Public Health in Boston, investigated the long term protective effects of high fruit and vegetable diets by analyzing data on 71,790 women who participated in the Nurses' Health Study and 37,725 men in the Health Professionals' Follow-up Study. Both studies began in the mid-1980s and ran through 1998.
Both men and women who ate five or more servings of fruits and vegetables per day reduced their risk of a heart attack or stroke by 12% compared to individuals who did not eat fruits and vegetables.
Eating leafy green vegetables provided the greatest reduction in heart attack and stroke risk. Consuming just one serving of leafy greens per day decreased the risk by 11%. While a modest reduction in the development of any major chronic disease was also noted, total fruit and vegetable intake did not appear to be inversely associated with cancer risk.
Three studies published July 2004 indicate that diet greatly affects your risk for stroke. Two of these studies, one focused on men, the other on women, underscore the importance of a diet rich in fruits and vegetables in preventing stroke. A third suggests that eating fish as little as 1 to 3 times per month may protect against ischemic stroke (the type of stroke caused by an interruption of blood supply to part of the brain).
Research data collected on 22,071 men, followed for 13 years in the Physician's Health Study, indicates that eating carotenoid-rich fruits and vegetables significantly reduces a man's risk of ischemic stroke.
The Harvard team analyzed blood samples from stroke patients and controls and found that the men whose blood levels of carotenoids (alpha-carotene, beta-carotene, lycopene, lutein and beta-cryptoxanthin), were in the lowest 20% had a much higher risk of ischemic stroke.
Low blood levels of alpha carotene were associated with a 41% increased risk for ischemic stroke, of beta-carotene with a 38% increased risk, and of lycopene with a 39% increased risk. No significant association was seen with beta-cryptoxanthin or lutein.
Since higher blood levels of carotenoids is simply a marker of higher fruit and vegetable intake, the researchers concluded that regular consumption of fruits and vegetables significantly lowers your risk of ischemic stroke.
Another Harvard research team examined the relationship between overall dietary patterns and risk of stroke in a study population of 71,768 women, followed for 14 years.
Two major dietary patterns were identified among the women: the "prudent" and the "Western". The prudent diet included higher intakes of fruits, vegetables, legumes, fish and whole grains, while the Western diet was high in red and processed meats, refined grains, sweets and desserts.
When women eating the prudent diet were compared, those with the highest scores were 22% less likely to have any kind of stroke (ischemic or hemorrhagic—the result of bleeding in the brain) compared to those with the lowest prudent scores. Women on the Western diet were also compared and fared badly regardless of whether their score was high or low. Those with the highest Western diet scores had a 58% increased risk of any type of stroke, but even those with the lowest Western diet scores had a 56% greater risk of stroke.
The bottom line: in women as well as in men, a diet higher in fruits and vegetables, fish, and whole grains is protective against stroke.
In addition to fruits and vegetables, eating fish may significantly lower your risk for stroke. Researchers reviewed data from 8 independent studies involving more than 200,000 subjects ranging in age from 34 to 103, and found that, eating fish
Avoid foods high in cholesterol and saturated fats.
The type of diet shown to contribute to the greatest death rate from heart disease is high in saturated fats, hydrogenated oils, animal products, refined foods and vegetable oils.
The diet shown to prevent and even reverse heart disease is a diet based on healthy foods--whole fruits, vegetables, legumes, and grains; cold water fish, and cold-pressed, extra virgin olive oil.
Significantly reduces blood cholesterol levels by several mechanisms.
Results published in the February 2004 issue of the Archives of Internal Medicine of an analysis of 10 prospective studies from the U.S. and Europe show that dietary fiber from cereals and fruits is associated with reduced risk of heart disease. Combining the studies gives extra credence to this conclusion since it pools very large numbers of participants and cases of heart disease. Among almost 100,000 men and the more than 245,000 women who participated in these 10 studies, for every ten grams of daily fiber consumed from cereals and fruits, their risk of all coronary disease dropped 14%, and their risk of death from heart attack dropped 27%.
Phytosterols are compounds found in plants that have a chemical structure very similar to cholesterol, and when present in the diet in sufficient amounts, are believed to reduce blood levels of cholesterol, enhance the immune response and decrease risk of certain cancers.
Phytosterols beneficial effects are so dramatic that they have been extracted from soybean, corn, and pine tree oil and added to processed foods, such as "butter"-replacement spreads, which are then touted as cholesterol-lowering "foods." But why settle for an imitation "butter" when Mother Nature's nuts and seeds are a naturally rich source of phytosterols—and cardio-protective fiber, minerals and healthy fats as well?
In a study in the November 2005 issue of the Journal of Agricultural and Food Chemistry, researchers published the amounts of phytosterols present in nuts and seeds commonly eaten in the United States.
Sesame seeds had the highest total phytosterol content (400-413 mg per 100 grams), and English walnuts and Brazil nuts the lowest (113 mg/100grams and 95 mg/100 grams). (100 grams is equivalent to 3.5 ounces.) Of the nuts and seeds typically consumed as snack foods, pistachios and sunflower seeds were richest in phytosterols (270-289 mg/100 g), followed by pumpkin seeds (265 mg/100 g).
Plant sterol-enriched margarines, such as Benecol, contain trans fats despite their claim to be trans fat-free. This misleading claim can legally be made because under the new 2006 regulations that demand the disclosure of trans fats, the FDA allows manufacturers to round to zero any ingredients that account for less than 0.5 grams per serving.
The new legislation also permits manufacturers to say "zero trans fats" on the label if a serving size contains a half gram or less of trans fatty acids. Benecol's ingredients include partially hydrogenated oil, which cannot be manufactured without creating trans fatty acids, and this margarine actually contains 0.5 grams of trans fats per 1 ½ teaspoon serving.
Recommendations for this product, which is endorsed by many mainstream organizations, are to use it "liberally". If you used Benecol on bread, vegetables, rice, potatoes, fish, etc., you could easily use more than 2 teaspoons at each meal and would be consuming 2 grams of trans fats daily from Benecol alone. To put this in perspective, a July 2002 report from the Institute of Medicine at the National Academy of Science declared that the upper limit for trans-fats in the diet should be zero. The consumption of 2-3 grams a day of trans fats increases the risk of coronary heart disease by 21%.
For those who would prefer to get their plant sterols from whole foods, these compounds are present naturally, although in smaller amounts than in sterol-enriched margarines, in all plant foods. The highest concentrations of plant sterols are found in unrefined vegetable oils, nuts, seeds, legumes, and whole grains.
In 2000, the FDA authorized a health claim describing the relationship between dietary intake of plant sterols and reduced risk of heart disease. That health claim states that "Foods containing at least 0.65 grams per serving of plant sterol esters, eaten twice a day with meals for a daily total intake of at least 1.3 grams, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease."
As the following table shows, a healthy way of eating featuring daily selections from the whole foods listed below can easily deliver 1.3 grams of cardio-protective plant sterols.
| Phytosterol Content of Selected Foods | ||
|---|---|---|
| Food | Serving | Phytosterols (mg) |
| Wheat germs | 1 ounce | 114-118 |
| Sesame seed | 1 ounce | 133-138 |
| Pumpkin seeds | 1 ounce | 88 |
| Pistachio | 1 ounce | 90-96 |
| Sunflower seeds | 1 ounce | 77-82.5 |
| Unrefined Canola oil | 1 TBS | 91 |
| Peanuts | 1 ounce | 62 |
| Wheat bran | 1/2 cup | 58 |
| Almonds | 1 ounce | 34 |
| Brussels sprouts | 1 ounce mg | 34 |
| Rye bread | 2 slices | 33 |
| Macadamia nuts | 1 ounce | 33 |
| Extra virgin olive oil | 1 TBS | 22 |
A B vitamin, niacin can reduce cholesterol and lipoprotein a levels, and has been shown to reduce incidence of heart attack.
Best Food Sources of Niacin: Brewer's yeast, rice bran, wheat bran, peanuts with skin, liver, trout, mackerel, swordfish, turkey, salmon.
A fat-soluble antioxidant, Vitamin E prevents oxidation of LDL cholesterol, prevents the growth of blood vessel plaques, and has been shown to reduce the risk of heart attack and deaths related to heart disease.
Best Food Sources of Vitamin E: wheat germ oil, sunflower seeds, safflower oil, almonds, sesame oil, wheat germ, peanuts, olive oil, soybean oil.
The body's primary water-soluble antioxidant, vitamin C is needed for the proper function of blood vessels, regenerates vitamin E, and can help decrease cholesterol levels. High dietary intake of vitamin C is associated with a decreased risk of death due to coronary artery disease.
Best Food Sources of Vitamin C: sweet peppers, kale, parsley, broccoli, Brussels sprouts, cabbage, strawberries, kiwifruit, papayas, spinach, oranges, grapefruit.
A powerful antioxidant in its own right, beta-carotene is also used by the body to produce vitamin A, which is often described as the anti-infective vitamin. A theory currently gaining acceptance in the scientific community is that viral infection may be a significant contributing factor in heart disease. Protection against infection and free radicals may explain why a high dietary intake of beta-carotene is associated with a reduced risk of fatal heart attack.
Best Food Sources of Beta-Carotene: carrots, sweet potatoes, butternut squash, mangoes, hubbard squash, cantaloupe, apricots, broccoli.
Whether it is tomatoes' lycopene or some other compound(s) found in tomatoes is not yet known, but Australian research published in the August 2004 issue of the prestigious Journal of the American Medical Association suggests that tomato juice is an effective blood thinner.
In this study, 20 people with type 2 diabetes were given 250 ml (about 8 ounces) of tomato juice or a tomato-flavored placebo daily. Subjects had no history of clotting problems and were taking no medications that would affect blood clotting ability. After just 3 weeks, platelet aggregation (the clumping together of blood cells) was significantly reduced among those drinking real tomato juice, while no such effect was noted in those receiving placebo.
In an interview, lead researcher Sherri Lazarus explained, "Diabetes is a multi-faceted disease with problems such as glucose intolerance, high blood pressure, high cholesterol and high triglycerides, and the less talked about hyperactive platelets.
Platelets are the parts of blood responsible for the preservation of healthy blood vessels. When the health of blood vessels is impaired, as in the case of diabetes, platelets stick to the lining of the vessel wall, which, over time, can lead to the development of cardiovascular disease. Aggregation is the clumping together and clotting of platelets. We looked at how susceptible the platelets were to clotting before and after the people with type 2 diabetes had taken tomato juice."
Although dietary strategies have been developed to address other known cardiovascular risk factors, currently there is no dietary strategy aimed at reducing high platelet activity. Tomato juice may be just what the doctor should order. While of special benefit for those with type 2 diabetes who are at increased risk of cardiovascular disease, the blood thinning effects of tomato juice are noteworthy for anyone at higher risk of blood clot formation. Persons with atherosclerosis or high cholesterol, those whose work involves traveling long distances, who have recently undergone a surgical procedure or who smoke would benefit. But be sure to choose a low-sodium tomato juice; many "regular" tomato juice products are loaded with artery-unfriendly sodium.
Both blond and red grapefruit can reduce blood levels of LDL (bad) cholesterol, and red grapefruit lowers triglycerides as well, shows a study published in the March 2006 issue of the Journal of Agricultural and Food Chemistry.
Israeli researchers from the Hebrew University in Jerusalem first tested the antioxidant potential of blond and red grapefruits and then their cholesterol-lowering potential in humans. The test tube research showed that red grapefruit contains more bioactive compounds and total polyphenols than blond, but both grapefruits are comparable in their content of fiber, phenolic and ascorbic acids, and the flavonoid, naringinen, although red grapefruit contains slightly more flavonoids and anthocyanins.
When consumed daily by humans, both grapefruits appear to lower LDL cholesterol in just 30 days. Blood cholesterol levels were measured at the outset of the trial period and after 30 days in 57 patients, aged 39-72 years, with high cholesterol. These subjects were randomly divided into three equal groups. Those in the first group added red grapefruit to their daily diet; those in the second group supplemented their diet with blond grapefruit, and the third group, acting as a control, ate no grapefruit.
After 30 days, cholesterol levels in both the red and blonde grapefruit groups had dropped significantly: total cholesterol by 15.5% in those eating red grapefruit and 7.6% in those eating blond grapefruit; LDL cholesterol by 20.3% and 10.7% respectively; and triglycerides by 17.2% and 5.6% respectively. No changes were seen in the control group.
Both red and blond grapefruits both positively influenced cholesterol levels, but red grapefruit was more than twice as effective, especially in lowering triglycerides. In addition, both grapefruits significantly improved blood levels of protective antioxidants. Red grapefruit's better performance may be due to an as yet unknown antioxidant compound or the synergistic effects of its phytonutrients.
In response to this rapid and very positive outcome, the researchers concluded that adding fresh red grapefruit to the diet could be beneficial for persons with high cholesterol, especially those who also have high triglycerides. One caveat, however: Compounds in grapefruit are known to increase circulating levels of several prescription drugs including statins. For this reason, the risk of muscle toxicity associated with statins may increase when grapefruit is consumed. (See our grapefruit Individual Concerns section for more information.)
Consuming a drink made from adding just 36 g (1.26 ounces) of a powder made from freeze-dried grapes to a glass of water daily for 4 weeks resulted in a wide variety of cardioprotective effects in 24 pre- and 20 postmenopausal women, shows a study published in the August 2005 issue of the Journal of Nutrition.
Frequent consumption of fish, especially cold water fish, which are rich in omega-3s, is associated with a decreased risk of heart attack. When part of a diet low in saturated fat, a high intake of omega-3 fats have also been found to help decrease cholesterol. Foods rich in omega-3s should be used to replace foods high in saturated fats such as meat and dairy products.
Feeling really grumpy? Eating more omega-3 rich cold water fish such as salmon, tuna, or sardines may help. A study published in the January 2004 issue of the European Journal of Clinical Nutrition found a statistically significant relationship between consuming fish rich in omega-3 fats and a lower hostility score in 3581 young urban white and black adults. Those with the highest intake of omega 3 fats had only a 10% likelihood of being among those with the highest hostility scores. Eating any fish rich in omega 3 fats compared to eating no omega-3-rich fish was also found to drop subjects' chances of being hostile by 12%. Cardiovascular protection is one reason this finding is important: hostility has been shown to predict the development of heart disease, and the young adults in this study were already also enrolled in the CARDIA (Coronary Artery Risk Development in Young Adults) study—a study that is examining how heart disease develops in adults.
Triglycerides are a form in which fat is carried in your bloodstream. In normal amounts, triglycerides are important for good health because they serve as a major source of energy. High levels of triglycerides, however, are associated with high total cholesterol, high LDL (bad) cholesterol and low HDL (good) cholesterol), and therefore, with an increased risk of cardiovascular disease.
In addition, high triglycerides are often found along with a group of other disease risk factors that has been labeled metabolic syndrome, a condition known to increase risk of not only heart disease, but diabetes and stroke. (Metabolic syndrome is the combined presence of high triglycerides, increased blood pressure, high blood sugar, excess weight, and low HDL (good) cholesterol.)
| Triglyceride Levels | |
|---|---|
| Less than 150 mg/dL | Normal |
| 150-199 mg/dL | Borderline-high |
| 200-499 mg/dL | High |
| 500 mg/dL | Very High |
*Note: Triglycerides are most accurately measured after an 8-12 hour fast.
In this 6-month study involving 142 overweight men and women with high triglycerides, subjects were divided into 5 groups, one of which served as a control group, 2 of which ate 2 servings of fish high in omega-3s while also replacing their normal household fats with fat high in sunflower (Group 1) or canola oil made from rapeseed (Group 2), and 2 of which ate 2 weekly servings of white fish while also replacing their normal household fats with ones high in sunflower (Group 3) or canola oil made from rapeseed (Group 4).
Canola oil also provides some omega-3 fats, with an omega-6:omega-3 ratio of 2:1, while sunflower oil contains omega-6, but no omega-3 fats.
At the end of the study, triglyceride levels had dropped 6.6% in the omega-3-rich fish groups combined. Triglycerides dropped most—10.4%—in those consuming omega-3-rich fish and canola oil. In those eating omega-3-rich fish and sunflower oil, triglycerides dropped 2.8%. Bottomline: A healthy way of eating that incorporates at least 2 weekly servings of fish and other food sources of omega-3 fats, such as flaxseed or canola oil, may significantly lower triglyceride levels. Replacing normal household fats with flaxseed oil, in which the ratio of omega-6:omega:3 fats is 1:4, might result in an even larger drop in triglyceride levels.
Best Food Sources of Omega-3 Fats: cold-water fish such as salmon and cod and their oils, flaxseed, flaxseed oil, walnuts, purslane.
These stable fats, which are found in highest concentrations in olive oil, decrease the oxidation of LDL cholesterol, help reduce cholesterol levels, and may partly explain why the "Mediterranean Diet," which is high in monounsaturated fats as well as whole foods, is protective against heart disease. Use olive oil to replace saturated fats (butter), trans-fats (margarine), and refined vegetable oils in cooking and salad dressing. Best Food Sources of Monounsaturated Fats: olive oil, high oleic safflower oil, high oleic sunflower oil, canola oil, grapeseed oil, avocado.
It's likely the abundance of polyphenols in extra virgin olive oil, rather than its monounsaturated fatty acids, are responsible for its well known cardiovascular benefits.
And its rich supply of polyphenols, which are known to have anti-inflammatory, antioxidant and anticoagulant actions, may also be central to emerging evidence that olive oil's protective effects extend to colon cancer and osteoporosis.
Research conducted by Dr. Juan Reno and colleagues at the Reina Sofia University Hospital, Cordoba, Spain, and published in the November 2005 issue of the Journal of the American College of Cardiology, investigated the effects of virgin olive oil on endothelial function in 21 volunteers with high cholesterol levels.
The endothelium, although just a one-cell thick layer of flat cells that lines the inner wall of all blood vessels, may be the critical player in cardiovascular health. Among its many functions, the endothelium orchestrates the mechanics of blood flow, and regulates blood clot formation and the adhesion of immune cells to the blood vessel wall (one of the first steps in the formation of plaque).
Normally, after a meal, endothelial function is impaired for several hours. Blood vessels become less elastic, and blood levels of free radicals potentially harmful to cholesterol (lipoperoxides and 8-epi prostaglandin-F2) rise.
But when the subjects in this study ate a breakfast containing virgin olive oil with its normal high phenolic content (400 ppm), their endothelial function actually improved, blood levels of nitric oxide (a blood vessel-relaxing compound produced by the endothelium) increased significantly, and far fewer free radicals were present than would normally be seen after a meal.
When they ate the same breakfast containing the same type of virgin olive oil with its phenolic content reduced to 80 ppm, the beneficial effects were virtually absent, and concentrations of cholesterol-damaging free radicals increased. The results of this study underscore the importance of knowing how to select, store and serve your olive oil to maximize its polyphenol content. For all the information you need, see our How to Select and Store section in Olive oil.
Soybeans and foods made from them have been found to significantly decrease the risk of heart disease and heart attack, can help prevent the oxidation of LDL cholesterol, and lower LDL and total cholesterol, triglyceride levels, and risk of blood clots. Soy may also increase HDL (beneficial) cholesterol levels.
A study published in the July 2003 issue of the British Journal of Nutrition suggests that diets high in soy protein also protect against atherosclerosis by increasing blood levels of nitric oxide, a small molecule known to improve blood vessel dilation and to inhibit oxidative (free radical) damage of cholesterol and the adhesion of white cells to the vascular wall (two important steps in the development of atherosclerotic plaques).
In this study, when researchers gave mice bred to be apoliprotein-E deficient a purified diet containing either casein, the principal protein in dairy products, soy protein or rice protein, the mice given casein developed the largest atherosclerotic lesions. (In humans as well as animals, apolipoprotein E plays an important role in cholesterol transport, so a deficiency of this protein increases risk for the development of atherosclerosis.) Mice given soy or rice protein fared much better. In trying to understand why, the researchers evaluated blood levels of nitric oxide. Mice fed either soy or rice protein diets were found to have increased blood levels of L-arginine (the amino acid that the body uses to produce nitric oxide) and nitric oxide metabolites when compared to those given casein-based feed. However, the L-arginine content of the soy and rice diets was not high enough to explain the amount of protective benefit they conferred, so the researchers concluded that these foods must also contain other protective compounds.
While recent research has confirmed that soy's isoflavones do not lower cholesterol, a study published in the March issue of the Journal of Nutrition shows that soy protein does lower heart disease risk by increasing the size of LDL cholesterol particles. Small dense LDL is the most dangerous form of cholesterol, while large LDL, especially when accompanied by adequate supplies of HDL (a ratio of 4 LDL:1 HDL is considered ideal) is considered much less risky.
In this study, conducted at the Jean Mayer USDA Human Nutrition Center on Aging at Tufts University, researchers found that people who ate diets high in soy protein significantly increased their LDL particle size compared to periods when they ate diets high in animal protein.
Study participants, all of whom had high cholesterol, were given four different diets, each for a period of six weeks: soy protein with no isoflavones, soy protein enriched with isoflavones, animal protein with no added isoflavones, and animal protein with added isoflavones.
While isoflavones had no effect, soy protein consumption resulted in a decrease in the amount of small dense LDL and an increase in larger LDL particles compared to animal protein—a significantly less risky cholesterol profile.
Some goods soy foods include organic tofu, tempeh, soymilk, edamame (soybeans), roasted soybeans, and soy miso.
Soy foods may offer special benefits for the hearts and bones of premenopausal women, suggest two studies conducted at Wake Forest University Baptist Medical Center and presented at the annual meeting of the North American Menopause Society, Washington, D.C., October 6-9, 2004. The results of these studies indicate a beneficial synergy between isoflavones, the weakly estrogenic compounds in soy, and the body's own estrogen in decreasing cholesterol and increasing bone mass.
In the first study, cholesterol levels in monkeys fed a soy-based diet were improved compared to those of monkeys given a diet of milk and animal protein—and the most improvement occurred in those monkeys at highest risk for heart vessel disease. A low ratio of total cholesterol to HDL (good) cholesterol is considered healthier. In monkeys at highest risk for heart disease, the cholesterol ratio decreased by 48% in those given soy compared to those receiving milk and animal protein. Even in the monkeys at low risk for atherosclerosis that ate soy, the cholesterol ratio dropped 33%.
Lead researcher in this study, Jay Kaplan, PhD, noted that a 48% drop in the cholesterol ratio would likely equate to a 50% reduction in the size of plaques in the arteries, which can rupture causing heart attacks and strokes. He also added, "Studies have shown that heart vessel disease, or atherosclerosis, begins in the 30s and 40s in women. From our work in monkeys, we believe the time to prevent cardiovascular disease in women is before menopause, not after. Soy seems to provide a potent protection in monkeys, in terms of cholesterol levels, which is a good marker for general cardiovascular risk. We presume the benefit would apply to premenopausal women as well."
In the second study, monkeys eating soy were found to have an increase in bone mass compared to those not given soy. According to lead researcher in this study, Cynthia Lees, D.V.M., Ph.D., "The increase was small, but this suggests the possibility that if women consumed soy on a regular basis before menopause, it could benefit their health after menopause." Kaplan also noted that because the soy-estrogen combination caused improvements in both cholesterol and bone, it might also positively impact other areas of the body affected by estrogen, including the brain.
In both 12 month long studies, the monkeys were selected to represent women in their 30s and 40s. Half consumed soy with isoflavone levels equal to a human intake of approximately 129 milligrams a day—about twice the amount typically consumed by women in Asia.
Next on the researchers' agenda will be a study using lower levels of isoflavones over a longer period of time to see if this will be as effective—an outcome that appears to already be supported in a human trial published in the November 2004 issue of the American Journal of Clinical Nutrition. In this study, which included 1033 pre- and postmenopausal women (361 meat-eaters, 570 vegetarians, and 102 vegans), eating moderate amounts of soy foods as part of a regular diet was associated with a lower ratio of total to LDL cholesterol, but not with a lowering in the level of beneficial HDL cholesterol. In those women eating 6 or more grams of soy protein daily, blood levels of LDL cholesterol were 12.4% lower than those in women who ate less than .5 grams of soy protein daily.
Best Soy Foods: organic edamame (soybeans), tofu, tempeh, soy milk.
Needed for the proper function of blood vessels, zinc may also slow the growth of plaques.
Best Food Sources of Zinc: fresh oysters, ginger root, ground round steak, lamb chops, pecans, split peas, Brazil nuts, beef liver, egg yolk.
Magnesium
Needed for normal blood vessel tone and function, magnesium may help lower high blood pressure, and may decrease risk of heart attack.
Best Food Sources of Magnesium: kelp, wheat bran, wheat germ, almonds, cashews, blackstrap molasses, Brewer's yeast, kiwifruit.
These three B vitamins work together to prevent the accumulation of homocysteine, an intermediate compound produced during the methylation cycle that can damage the arterial wall. Elevated levels of homocysteine are found in approximately 20-40% of patients with heart disease.
Best Food Sources of Folic Acid and B6: Brewer's yeast, soy flour, wheat germ. Best Food Sources of B12: liver, clams, oysters, sardines, egg yolk.
This mineral may decrease the growth and development of vessel plaques, and also good for lowering high blood pressure. To obtain the maximum benefits from an increased potassium intake, it is important to reduce the amount of sodium in the diet. Most sodium in the American diet comes from processed, convenience and snack foods.
Best Food Sources of Potassium: dulse, kelp, sunflower seeds, wheat germ, almonds, raisins, parsley, Brazil nuts, peanuts, dates, figs, kiwifruit, avocado, pecans, yams, Swiss chard, soybeans, garlic, spinach, English walnuts, millet, beans, mushrooms, potato with skin, broccoli.
An amino acid found mainly in fish, taurine may decrease cholesterol levels and lower high blood pressure.
Best Food Sources of Taurine: fish - especially cold water fish like salmon and cod.
Powerful antioxidant compounds found in many fruits and vegetables, bioflavonoids are associated with decreased risk of death from cardiovascular disease.
Best Food Sources: red grapes, onions, apples, and citrus fruits.
Allium family vegetables contain compounds that have been shown to lower cholesterol levels, lower blood pressure in cases of hypertension, and slow the rate of plaque growth.
Best Sources of Allium Vegetable Compounds: Fresh, raw garlic and onions contain the highest amounts of these beneficial compounds.
Excessive dietary intake of foods rich in saturated fat and cholesterol, which are found primarily in animal products, is associated with increased risk of atherosclerosis and heart disease. For maximum health benefit, limit intake of saturated fat while increasing intake of heart-protective whole foods - vegetables, fruits, nuts, seeds, legumes, cold-water fish, whole grains.
High levels of stored iron are associated with increased free radical production and therefore increased risk of heart attack, especially in those with high cholesterol levels. Hemochromatosis, a condition of iron overload, is common in Caucasian males. Supplements containing iron should not be taken by men or post-menopausal women who are at risk for atherosclerosis, unless they have been diagnosed with anemia by a physician. Since blood loss results in iron loss, menstruating women may safely consume a multiple mineral and vitamin supplement which contains 15-30 mg of iron.
Vegetable oils that have been chemically transformed into solid fats, trans-fatty acids (also called hydrogenated fats) increase LDL cholesterol and lipoprotein a levels, may be more damaging to the heart and blood vessels than saturated fat, and should be eliminated from the diet. These unnatural fats are not found in whole foods, but are the predominant component in margarine and are frequently added to processed foods, baked goods, coffee creamers, and snack foods.
Heart disease, the leading cause of death in adults in the United States today, affects 60 million Americans. An estimated 1,100,000 new or recurrent heart attacks occur annually, which translates into the grim statistic that every 20 seconds a person in the U.S. has a heart attack, and one-third of these attacks lead to death.
The main underlying cause of heart disease, atherosclerosis, begins early (in some cases, as early as childhood), and slowly progresses into full-blown heart disease.
Atherosclerosis is the build-up of fatty deposits in the walls of the arteries. When these deposits, or plaques, build up in the blood vessels of the heart, they cause coronary artery disease, which can lead to a heart attack. When they build up in the blood vessels of the brain, they cause cerebral artery disease, which can lead to a stroke.
Physiological indicators of increased risk for atherosclerosis include: high blood pressure, high cholesterol (especially oxidized LDL cholesterol, the form that causes the most harm), high blood levels of Lp(a) (lipoprotein a), obesity, high levels of homocysteine, and insulin resistance, especially when advanced to the level of type 2 diabetes mellitus. Through genetic inheritance, family history plays a role in the development of atherosclerosis, but a number of other risk factors related to diet and lifestyle are of equal or greater importance.
Heart disease accounts for approximately 30-40% of all deaths in industrial nations every year and is the leading cause of death of adults in these areas. Vascular disease alone accounted for close to 1 million deaths in 1994. Ischemic heart disease is currently very common in the U.S., and occurs in approximately 80% of all people over the age of 70 years. Treatment of coronary artery disease and its risk factors, including hypertension and high cholesterol, accounts for a large portion of health care spending and medication use.
Although the deaths and symptoms caused by atherosclerosis tend to occur later in life, the condition itself typically develops fairly slowly and may begin as early as childhood. The good news is that early prevention of this disease and reduction of the associated risk factors has been shown to significantly decrease risk of both fatal and non-fatal heart attack.
Atherosclerosis is generally considered a multi-factorial disease, meaning that many possible causes contribute to its development and advancement. Genetics plays a role in the development of heart disease, as evidenced by its tendency to run in families, but research has clearly shown that the way one lives and eats plays a large or even more important role. No family history of heart disease is not a guarantee of safety for an individual with an unhealthy diet and lifestyle. On the positive side, a strong family history of heart disease does not doom one to develop it. Genetics is, at worst, an indicator of increased risk, which can be significantly lowered by health-promoting dietary and lifestyle choices.
Atherosclerosis is a disease that involves the development of cholesterol-filled plaques, called atheromas, in the walls of the blood vessels, causing the vessels to lose their elasticity and become sclerotic, or hardened. These atheromas are especially problematic when they develop in the blood vessels of the heart, also known as the coronary arteries, where they may decrease the amount of blood that is available to feed the heart muscle, or where they may eventually lead to heart attack, also called myocardial infarction (MI), heart damage, and possibly even death. Atheromas are believed to develop slowly over a prolonged period of time. Although the exact mechanism of how they start and develop is not completely understood, research in humans and animals has lead to the creation of a model for how the condition progresses. The first step in the process appears to be some type of injury to the wall of the vessel. The cause of this initial injury is currently unknown, though it may be due to certain infections, high levels of oxidized cholesterol, high levels of homocysteine, or a number of other factors. Once the initial injury occurs, cholesterol circulating in the bloodstream starts to be deposited at the site of injury in the blood vessel wall, where inflammatory chemicals oxidize it.
The oxidized cholesterol particles and the injury itself attract certain immune cells, called monocytes and macrophages, which take in large quantities of the oxidized cholesterol, becoming quite large. They also become activated and begin releasing inflammation-related chemicals called cytokines. The cytokines cause the cells of the vessel wall, also called endothelial cells, to produce adhesion molecules on the surfaces of their cell membranes. Adhesion molecules are sites where more immune cells can bind. The cytokines also attract other immune cells, which then bind to the adhesion molecules and are taken into the blood vessel wall, where they trigger an increase in inflammatory response.
As the build-up of immune cells and oxidized cholesterol continues in the arterial wall, the cytokines and inflammatory chemicals attract another type of cell, called smooth muscle cells, which travel to the site of the developing plaque, enter the blood vessel wall, take in oxidized cholesterol, and begin to divide. In addition, the cells start to produce collagen, the main protein in connective tissue, which adds to the plaque.
As the process continues, the atheroma, which grows larger and larger, is now comprised of enlarged macrophages and monocytes filled with oxidized cholesterol, dividing smooth muscle cells, and collagen, as well as the initial endothelial cells. Calcium now begins to be deposited, making the atheroma sclerotic or hardened, and inflexible.
Because blood vessels contain no nerves to signal their distress, the atheroma may grow very large for a long period of time before its presence is known. A large atheroma in the coronary vessels may start to block blood flow to the heart, leading to symptoms like shortness of breath or angina. Atheromas in the blood vessels leading to the brain may cause dizziness or lightheadedness. Generally, though, because they grow slowly enough for the body to compensate for the decreased blood flow, most atheromas don't cause any warning symptoms but make their debut into the individual's conscious awareness by causing a heart attack. In this stage, the blood vessel wall where the atheroma is attached breaks slightly, causing a release of blood into the surrounding tissue. In order to stop this blood loss, platelets clump together forming a blood clot, called a thrombus. A thrombus may also be caused by platelets that simply start to stick to the atheroma and then build up. If the thrombus stays where it is, it may grow large enough to cause a sudden blockage of blood flow in the artery. If it breaks loose from the atheroma, it is called an embolism, and it may travel down the blood vessel to a point where it is too big to pass and rapidly cut off blood supply at that spot.
Typically, the blockage of a vessel by a thrombus also involves spasm of the artery, further decreasing the blood flow. When this occurs in the blood vessels in the head, it is called a stroke and damage occurs due to lack of oxygen to the brain tissue that is normally supplied by the blocked vessel. This damage may be slight and produce little lasting effects or may be great enough to cause severe permanent disability or even death. When the sudden blockage occurs in the coronary vessels, it causes damage to the cells of the heart muscle due to lack of oxygen. Components in the bloodstream then rapidly break down the clot so that blood may return to the area. Unfortunately, the damaged cells have released chemicals that attract and activate immune cells, which then quickly travel to the area and release more inflammatory chemicals, causing damage to more cells. Because of cascade of inflammation triggered by the immune cells, more damage occurs to the heart muscle after the blood flow returns than when the blood flow was blocked.
Many myocardial infarctions are mild and may even go unnoticed. In others, however, the damage to the heart muscle interferes with the normal beating of the heart, leading to ventricular fibrillation, a rapid and chaotic "fluttering" action of the heart muscle. This condition is called a cardiac arrest, and it is fatal if not immediately treated by emergency measures. Cardiac arrest is the main cause of death in patients with coronary artery disease.
High levels of cholesterol have been repeatedly associated with atherosclerosis and heart disease. Cholesterol is also found in high quantities in the atheromas seen in vascular disease.
Cholesterol is a necessary substance that is even produced by the body from fatty acids, especially saturated fats, in the diet. Ready-made cholesterol is also absorbed from foods derived from animals. From the bloodstream, cholesterol is taken up by cells and used to make cell membranes, certain hormones and vitamin D.
Cholesterol is produced by a number of steps involving several different enzymes. One of the main enzymes involved is called HMG Co-A reductase. This enzyme has the single most say-so over how much cholesterol is produced. HMG Co-A reductase usually works to produce just enough cholesterol for normal function, but sometimes, especially when the diet is high in saturated fats, it becomes a workaholic and contributes to elevated cholesterol levels. If the diet is also high in cholesterol-containing animal foods, then cholesterol levels can be raised even more.
Cholesterol is packaged into particles called low-density lipoproteins, or LDL cholesterol, and distributed throughout the body to where it is needed. High-density lipoprotein particles, or HDL cholesterol, then travels throughout the body collecting the extra cholesterol not used by cells. For this reason, HDL is often referred to as the "good" cholesterol.
Cholesterol in the body that is not used to produce hormones, vitamin D, or cell membranes is also eliminated by the liver. The liver converts the cholesterol to bile, which is stored in the gall bladder until it is needed in the intestines. When bile is released into the intestines, it aids digestion by making dietary fats easier to absorb. Much of the bile that passes into the intestines is reabsorbed and recycled for future use. If it binds to certain food substances, like fiber, however, it can pass out of the body and new bile must be produced from cholesterol to replace the bile that is lost.
Normally, cholesterol is not toxic to the body. It flows through the blood vessels without causing any damage or atheroma build-up. However, when cholesterol becomes oxidized, either by heat or free radicals before it is absorbed in the intestines, or by free radicals found in the body, it can become dangerous. Oxidized LDL cholesterol is directly toxic to endothelial cells. It increases the adhesion of monocytes and macrophages to vascular lesions, increases the proliferation of smooth muscle cells, increases platelet clumping and thrombus formation, and inhibits the production of nitric oxide, a messenger chemical needed for vasodilation.
Macrophages and monocytes normally only take in small amounts of unoxidized cholesterol, but when they are exposed to oxidized cholesterol, they take in large amounts, causing them to greatly increase in size. A high blood level of oxidized LDL cholesterol, therefore, is a strong contributing factor for the production and growth of atheromas and the progression of heart disease.
Lp(a) is a mix of protein molecules and lipid molecules found in the body. High levels have been shown to be a separate risk factor for cardiovascular disease and are associated with an increased risk of coronary thrombosis, a blood clot in the arteries of the heart.
One way in which Lp(a) may cause problems is in the inhibition of a process called fibrinolysis. Fibrinolysis involves the break-down of excess collagen, connective tissue, and blood clots. By inhibiting fibrinolysis, Lp(a) contributes to the build up of collagen and therefore the growth of atheromas, as well as increasing the risk of thrombus formation and heart attack or stroke.
Elevated blood levels of homocysteine are seen in patients with vascular disease and are associated with an increased risk of stroke, coronary artery disease, and peripheral vascular disease.
Homocysteine is a substance formed during a normal metabolic process in the body called the methylation cycle. Almost immediately after its production, a large percentage of homocysteine is usually transformed into the amino acid methionine. This conversion process, however, requires certain vitamins, including vitamin B12, vitamin B6, and folic acid. Deficiency of these vitamins results in increased homocysteine levels by decreasing homocysteine's conversion to methionine.
Homocysteine levels can also be elevated for other reasons. Mutations in the genes that regulate the process of converting homocysteine back to methionine account for a number of cases of elevated homocysteine. As many as 35-40% of Caucasians carry a mutated copy of one of these genes, which may then cause elevations in homocysteine levels. In many of these patients, simply getting extra amounts of vitamin B6, B12 and folic acid will keep homocysteine levels low. Even in persons without genetically caused difficulties, inadequate intake of any or all of these required vitamins can result in elevated homocysteine levels. Some studies have shown that this may account for as many as 66% of cases.
Another cause of elevated homocyteine levels is chronic kidney failure, since the kidneys are a major site of homocysteine metabolism. Levels may also be raised by certain medications including methotrexate, phenytoin, carbamazepine, nitrous oxide, theophylline, and 6-azauridine triacetate, or by other medical conditions including acute lymphoblastic leukemia and psoriasis. Smoking, drinking caffeinated coffee, and chronic high alcohol intake can raise levels as well.Homocysteine has been shown to cause damage to the endothelium, increased division and proliferation of smooth muscle cells, and increased oxidation of LDL cholesterol and other lipids. By increasing levels of free radicals, which damage endothelial cells, homocysteine can lead to reduced production by these endothelial cells of nitric oxide (NO), a chemical messenger necessary for the normal dilation of blood vessels. NO also helps to decrease the proliferation of the smooth muscle cells, reduce the binding of immune cells to atheroma sites, and decrease platelet clumping. Homocysteine has been shown to make the endothelium more prone to the development of blood clots.
Hypertension, or high blood pressure, affects as much as 1/3 of the population of industrialized nations and has been shown to greatly contribute to the formation and progression of heart disease. Patients with hypertension are much more likely to have a fatal coronary than those without. It is currently unknown why or how high blood pressure contributes so much to the development and fatality of heart disease, but patients who are able to decrease their blood pressure to normal levels, especially without the use of medications, are at much lower risk of a fatal event than those who are either unable to lower their blood pressure or require certain medications to do so. In addition, some blood pressure medications have actually been associated with an increased risk of fatal heart attack, though it is unknown why.
Insulin resistance is one of the main problems associated with type 2 diabetes. It is also seen in a condition called Syndrome X, which mainly occurs in post-menopausal women and primarily affects individuals in their 40s and 50s. Insulin resistance means that cells don't respond normally to insulin.
Normally, insulin produced by the body binds to special insulin receptors on cell membranes, triggering the cells to absorb sugar, or glucose, from the blood stream. In some people, however, a couple of things can go wrong. The pancreas, which produces insulin, may start to produce insulin that is defective and does not bind to the repectors properly. Or, the cells of the body may produce defective receptors that do not allow the insulin to bind properly. Although genetics seems to play a role in both these causes of insulin resistance, evidence strongly suggests that certain dietary and lifestyle habits are more important in the development of this condition.
When the insulin-resistant cells fail to respond to insulin, blood sugar levels build up. To try to compensate for the cells' resistance, the body produces even more insulin, leading to elevated insulin levels as well. Both elevated blood sugar and elevated insulin can be damaging to the linings of blood vessels, so people with insulin resistance are at much higher risk of developing atherosclerosis. They also progress to heart disease and heart attack much more rapidly. One reason for this is that insulin-resistant patients are much more susceptible to damage caused by free radicals. Studies have shown that type 2 diabetes patients have much higher levels of free radicals than normal controls. High levels of free radicals cause an increase in the oxidation of LDL cholesterol, initiating the formation and development of atheromas. For more information on insulin resistance, just click on the following link: type 2 diabetes.
Obesity is also a risk factor for high blood pressure and insulin resistance and may contribute to atherosclerosis through those risk factors. People who are obese also generally have diets that are high in saturated fats and cholesterol, which contribute to atherosclerosis, and low in nutrients such as B vitamins, fiber, and antioxidants, which are protective. They also tend to not get adequate exercise, which has been shown to be helpful in the prevention of heart disease.
Typically, the effects of different risk factors are more than additive, meaning that a person who has two risk factors usually has more than twice the risk than someone with just one risk factor. Eliminating as many of these factors as possible will greatly decrease an individual's risk of heart disease and cardiovascular death.
A diet high in cholesterol and saturated fats, and low in fruits, vegetables, whole grains, legumes, and fiber is associated with heart disease. Populations that eat traditional diets high in vegetables, fiber, and whole grains tend to have much lower rates of heart disease and vascular disease than populations that eat high amounts of cholesterol and saturated fats from animal products.
Research published in the August 2006 issue of the Journal of the American College of Cardiology shows that eating a meal rich in saturated fats inhibits the activity of "good" HDL cholesterol to protect against inflammation, while a meal rich in polyunsaturated fats, abundant in a Mediterranean diet, boosts HDL's protective action.
Previous studies have shown that saturated fat (found in meat, dairy products and palm oil) can increase the amount of cholesterol in the blood, increasing risk of developing cardiovascular disease.
Lead author Stephen Nicholls, a cardiologist at Cleveland Clinic in Ohio, said, "The take-home, public-health message is this: Its further evidence to support the need to aggressively reduce the amount of saturated fat consumed in the diet."
This new research expands our understanding of how saturated fats promote heart disease by delivering a double destructive whammy. These fats not only raise levels of "bad" LDL cholesterol, but actually inhibit the protective action of "good" HDL cholesterol.
The researchers recruited 14 adults, who were given a meal containing either polyunsaturated or saturated fat on two different occasions. Both meals contained the same number of calories. Both before and 6 hours after the meal, blood samples were taken, and the action of HDL on the production of molecules associated with inflammation was evaluated.
The researchers looked at levels of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in the endothelium (the lining of the inner wall of blood vessels). These two molecules are involved in the immune system response, and an increase in their levels is associated with inflammation and an increased probability that LDL-cholesterol will be damaged. (Only once damaged does LDL adhere to the blood vessel wall, beginning the process that develops into atherosclerosis.)
One of HDL-cholesterol's protective actions is inhibiting the production of ICAM-1 and VCAM-1.
But, the HDL-cholesterol collected after the saturated fat meal was eaten was less effective at inhibiting the expression of ICAM-1 and VCAM-1 than HDL isolated from blood samples taken before eating.
In contrast, HDL collected after eating the polyunsaturated meal was more effective in inhibiting ICAM-1 and VCAM-1 expression than even the HDL collected before eating.
Lead researcher, Dr. David Celermajer from the Heart Research Institute, Sydney, noted, "Most everyone concentrates on the amount of "good" cholesterol. This study shows that its quality may be very important too, in determining its protective ability."
"Most people also measure cholesterol and its fractions with people fasting - but it seems that its quality after a meal (and most of us spend a lot of time in the post-absorptive state) may be important to consider, too," Celemajer added.
The researchers also looked at changes in blood flow after eating. Blood flow decreased by 2.2% after eating the saturated fat meal, but the polyunsaturated fat meal only reduced blood flow by 0.9%.
This study demonstrates that, depending on what we choose to eat, we can actually change the activity of our HDL-cholesterol, either boosting or lowering its protective ability.
The Standard American Diet, which is high in saturated fat from meat, full-fat dairy products and processed foods containing palm oil, renders our HDL less able to protect us. In contrast, a Mediterranean diet, rich in polyunsaturated fats from nuts, seeds, cold water fish, whole grains, and legumes such as soybeans, increases our HDL-cholesterol's protective ability.
The harmful effects of saturated fats on HDL may be one reason populations that consume large amounts of fish and fish oils in place of other animal meats and fats tend to have lower rates of cardiovascular disease and the associated mortality.
The Mediterranean diet, which is high in whole grains and vegetables, relatively high in monounsaturated fats (which are contained within olive oil), and relatively low in animal products has been shown to be protective against heart disease despite its fairly high levels of fat. This suggests that thetype of fat in the diet may be more important than the actual amount. While high levels of saturated fats from meat and dairy products and polyunsaturated fats from vegetable oils have been strongly associated with an increased risk of atherosclerosis and heart disease, high levels of monounsaturated fats, found abundantly in olive oil, and omega-3 fats, found abundantly in fish, have been associated with lower rates of atherosclerosis, suggesting that these fats may even be protective.
Nutrients that decrease the formation and progression of atheromas include:
Those nutrients, which recent scientific studies have shown to possess these benefical effects, are profiled below.
Soluble fiber acts to reduce cholesterol levels in several ways:
First, soluble fiber in the intestines binds to bile from the liver, so it is carried out of the body as waste instead of being reabsorbed. In order for the body to make more bile, which is necessary for digestion, it must break down more cholesterol, removing it from the bloodstream. In addition, because bile is needed for the absorption of cholesterol from food, binding the bile makes it less able to assist in cholesterol absorption, so less dietary cholesterol is absorbed from the food.
Secondly, when normal levels of bacteria are present in the colon, they are able to break down some of the soluble fiber into what are called short-chain fatty acids. In addition to being very good for the health of the colon cells, some short-chain fatty acids are absorbed into the bloodstream, where they travel to the liver and decrease the action of HMG Co-A reductase, one of the main enzymes involved in the production of cholesterol.
So, soluble fiber acts to reduce cholesterol levels by:
Some excellent food sources of fiber include raspberries, mustard greens, cauliflower, collard greens, broccoli, chard and turnip greens.
Click here for more food source of fiber.
Phytosterols are compounds found in plants that have a chemical structure very similar to cholesterol. When present in the diet in sufficient amounts, phytosterols have been shown to lower blood levels of cholesterol, enhance the immune response and decrease risk of certain cancers.
Phytosterols beneficial effects are so dramatic that they have been extracted from soybean, corn, and pine tree oil and added to processed foods, such as "butter"-replacement spreads, which are then touted as cholesterol-lowering "foods." But why settle for an imitation "butter" when Mother Nature's nuts and seeds are a naturally rich source of phytosterols—and cardio-protective fiber, minerals and healthy fats as well?
In the November 2005 issue of the Journal of Agricultural and Food Chemistry, scientists published the results of research analyzing the amounts of phytosterols present in nuts and seeds commonly eaten in the United States.
Sesame seeds had the highest total phytosterol content (400-413 mg per 100 grams), and English walnuts and Brazil nuts the lowest (113 mg/100grams and 95 mg/100 grams). (100 grams is equivalent to 3.5 ounces.)
Of the nuts and seeds typically consumed as snack foods, pistachios and sunflower seeds were richest in phytosterols (270-289 mg/100 g), followed by pumpkin seeds (265 mg/100 g).
The rich mixture of phytonutrients found in grapes—which includes flavans, anthocyanins, quercetin, myricetin, kaempferol, as well as resveratrol—is thought to be responsible for numerous beneficial effects seen on cholesterol metabolism, oxidative stress (free radical activity) and inflammation in a study published in the August 2005 issue of the Journal of Nutrition.
In this study, 24 pre- and 20 postmenopausal women who consumed a drink made from adding just 36 g (1.26 ounces) of a powder made from freeze-dried grapes to a glass of water daily for 4 weeks experienced a wide variety of cardioprotective effects including:
Both blond and red grapefruit can reduce blood levels of LDL (bad) cholesterol, and red grapefruit lowers triglycerides as well, shows a study published in the March 2006 issue of the Journal of Agricultural and Food Chemistry.
Israeli researchers from the Hebrew University in Jerusalem first tested the antioxidant potential of blond and red grapefruits and then their cholesterol-lowering potential in humans. The test tube research showed that red grapefruit contains more bioactive compounds and total polyphenols than blond, but both grapefruits are comparable in their content of fiber, phenolic and ascorbic acids, and the flavonoid, naringinen, although red grapefruit contains slightly more flavonoids and anthocyanins.
When consumed daily by humans, both grapefruits appear to lower LDL cholesterol in just 30 days. Blood cholesterol levels were measured at the outset of the trial period and after 30 days in 57 patients, aged 39-72 years, with high cholesterol. These subjects were randomly divided into three equal groups. Those in the first group added red grapefruit to their daily diet; those in the second group supplemented their diet with blond grapefruit, and the third group, acting as a control, ate no grapefruit.
After 30 days, cholesterol levels in both the red and blonde grapefruit groups had dropped significantly: total cholesterol by 15.5% in those eating red grapefruit and 7.6% in those eating blond grapefruit; LDL cholesterol by 20.3% and 10.7% respectively; and triglycerides by 17.2% and 5.6% respectively. No changes were seen in the control group.
Both red and blond grapefruits both positively influenced cholesterol levels, but red grapefruit was more than twice as effective, especially in lowering triglycerides. In addition, both grapefruits significantly improved blood levels of protective antioxidants. Red grapefruit's better performance may be due to an as yet unknown antioxidant compound or the synergistic effects of its phytonutrients.
In response to this rapid and very positive outcome, the researchers concluded that adding fresh red grapefruit to the diet could be beneficial for persons with high cholesterol, especially those who also have high triglycerides.
One caveat, however: Compounds in grapefruit are known to increase circulating levels of several prescription drugs including statins. For this reason, the risk of muscle toxicity associated with statins may increase when grapefruit is consumed. (See our grapefruit Individual Concerns section for more information.)
Niacin, also known as vitamin B3, has been shown to decrease the activity of HMG Co-A reductase, which leads to a decrease in the body's production of cholesterol. It also helps to increase the breakdown of cholesterol to bile, decreases the proliferation of smooth muscle cells, helps to prevent LDL oxidation, reduces platelet clumping, lowers lipoprotein a levels, and can increase HDL, or good cholesterol, levels by as much as 15-40%. Increasing HDL levels, particularly through diet, can significantly decrease atherosclerosis progression.Niacin use has been shown to decrease cholesterol levels by 10-26% and decrease myocardial infarction recurrence by 29%. Niacin given to patients after an acute myocardial infarction reduced non-fatal MI recurrence by 27% and decreased long-term overall mortality by 11%.
Excellent food sources of niacin include crimini mushrooms and tuna while very good sources include chicken, halibut, salmonm and asparagus.
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Cultures in which soy foods constitute a major portion of the diet typically have much lower rates of heart disease than cultures with a low consumption of soy. In addition to this epidemiological data, clinical studies have shown that soy foods are protective against the development of heart disease and its associated mortality. The beneficial effects found in these studies are due to an intake of whole soy foods and not the isolated soy components that are currently available in supplement form.
Soy foods have been shown to decrease LDL by 35-40% and total cholesterol levels by 30%, decrease triglyceride levels, and decrease platelet aggregation, reducing the risk of blot clots. Soy foods may also increase HDL cholesterol levels.
A study published in the July 2003 issue of the British Journal of Nutrition suggests that diets high in soy protein also protect against atherosclerosis by increasing blood levels of nitric oxide, a small molecule known to improve blood vessel dilation and to inhibit oxidative (free radical) damage of cholesterol and the adhesion of white cells to the vascular wall (two important steps in the development of atherosclerotic plaques).
In this study, when researchers gave mice bred to be apoliprotein-E deficient a purified diet containing either casein, the principal protein in dairy products, soy protein or rice protein, the mice given casein developed the largest atherosclerotic lesions. (In humans as well as animals, apolipoprotein E plays an important role in cholesterol transport, so a deficiency of this protein increases risk for the development of atherosclerosis.) Mice given soy or rice protein fared much better. In trying to understand why, the researchers evaluated blood levels of nitric oxide. Mice fed either soy or rice protein diets were found to have increased blood levels of L-arginine (the amino acid that the body uses to produce nitric oxide) and nitric oxide metabolites when compared to those given casein-based feed. However, the L-arginine content of the soy and rice diets was not high enough to explain the amount of protective benefit they conferred, so the researchers concluded that these foods must also contain other protective compounds.
Women's risk for cardiovascular disease increases after menopause, in part because levels of risk factors including homocysteine and excess body iron, tend to rise.
In this study (Hanson L, Engleman H, American Journal of Clinical Nutrition), researchers looked at the effect of soy protein, specifically soy's isoflavones and phytate, on CVD risk factors in 55 postmenopausal women. To do so, they randomly assigned the women to 1 of 4 soy protein (40 grams per day) groups: soy containing both its native phytate and native isoflavones, native phytate but low isoflavone, low phytate and native isoflavone, or low phytate and low isoflavone.
After just 6 weeks, women in the groups given soy protein with its native phytate had significant reductions in homocysteine and excess iron concentrations. Soy protein with native isoflavones had no effect.
Most interesting about this study is the fact that the phytate in soy, a compound which, because of its mineral-binding effects, has sometimes been considered problematic, that is responsible for some of the CVD-protective effects soy offers postmenopausal women. Once again, Mother Nature appears to have good reason for all the compounds found in whole foods.
Soy's beneficial cardiovascular effects also extend to men. A study published in the Journal of the American College of Nutrition (Sagara M, Kanda T) has investigated the effects of soy protein and soy isoflavones on blood pressure and cholesterol levels in 61 middle-aged Scottish men (aged 45 —59 years), at high risk of developing coronary heart disease. For five weeks, half the men consumed diets containing at least 20 grams of soy protein and 80 miligrams of soy isoflavones each day. The effects on their blood pressure, cholesterol levels, and urinary excretion of isoflavones were measured, and then compared to those of the other half of the men who were given a placebo diet containing olive oil.
The men consuming soy in their diet were found to have significant reductions in both diastolic and systolic blood pressure. Not only was their total blood cholesterol significantly lower, but their levels of HDL (good) cholesterol significantly increased. While the control group consuming the soy-free diet containing olive oil also experienced an increase in their HDL cholesterol levels, their blood pressure was not affected, nor did their levels of LDL (potentially harmful) cholesterol drop.
The researchers concluded that daily intake of at least 20 grams of soy protein including 80 mg of isoflavones for a minimum of 5 weeks would be effective in reducing the risk of cardiovascular disease in high-risk, middle-aged men.
While recent research has confirmed that soy's isoflavones do not lower cholesterol, a study published in the March issue of the Journal of Nutrition shows that soy protein does lower heart disease risk by increasing the size of LDL cholesterol particles. Small dense LDL is the most dangerous form of cholesterol, while large LDL, especially when accompanied by adequate supplies of HDL (a ratio of 4 LDL:1 HDL is considered ideal) is considered much less risky.
In this study, conducted at the Jean Mayer USDA Human Nutrition Center on Aging at Tufts University, researchers found that people who ate diets high in soy protein significantly increased their LDL particle size compared to periods when they ate diets high in animal protein.
Study participants, all of whom had high cholesterol, were given four different diets, each for a period of six weeks: soy protein with no isoflavones, soy protein enriched with isoflavones, animal protein with no added isoflavones, and animal protein with added isoflavones.
While isoflavones had no effect, soy protein consumption resulted in a decrease in the amount of small dense LDL and an increase in larger LDL particles compared to animal protein—a significantly less risky cholesterol profile.
Some goods soy foods include tofu, tempeh, soymilk, edamame (soybeans), roasted soybeans, and soy miso.
Taurine is an amino acid component of protein particularly common in fish protein. It has been shown to decrease elevated cholesterol levels by decreasing the absorption of cholesterol in the intestines as well as by increasing the conversion of cholesterol into bile, thereby removing it from the body. Studies have shown that those with higher intakes of taurine have a lower risk of ischemic heart disease mortality. It is suggested that people eat fish, a rich source of taurine, at least 5 days a week in order to gain the maximum benefit.
Best Food Sources of Taurine: Fish. Cold-water fish such as salmon and cod are recommended as these are also rich in beneficial omega-3 essential fatty acids.
Blood vitamin B6 levels tend to be lower in coronary artery disease and myocardial infarction patients, and some believe that low blood vitamin B6 levels may actually be useful as an indicator of risk for myocardial infarction. Vitamin B6 is one of the vitamins needed for the proper metabolism of homocysteine, discussed below.
Vitamin B6 may be beneficial to those trying to prevent cardiovascular disease for several other reasons:
Vitamin B6 has been shown in studies to decrease platelet clumping and thereby decrease risk of thrombosis.
Vitamin B6 supplement use has been shown to decrease LDL cholesterol levels by as much as 17%. Unfortunately, the use of excessive amounts of vitamin B6 in supplement form for long periods of time has been associated with the development of a neurological condition of decreased sensation in the hands and feet. These high levels are not attainable through dietary sources of vitamin B6 and only occur in those taking high levels of vitamin B6 supplements.
Some excellent food sources of vitamin B6 include bell peppers, turnip greens and spinach.
Click here for more food source of vitamin B6.
Vitamin E, the primary fat-soluble antioxidant in the body, is the antioxidant found in highest quantities in LDL cholesterol particles, which it protects from oxidation. Vitamin E is the main defender of lipids (fats) and is responsible for putting a halt to chain reactions of lipid peroxidation anywhere in the body. Vitamin E has also been shown to decrease platelet clumping, prevent the rupture of existing atheromas, decrease the migration of macrophages to atheromas, prevent the inhibition of NO production, and to decrease the expression of adhesion molecules on the surfaces of endothelial cells, thereby reducing the amount of binding that can occur with monocytes and other immune cells.
Studies have shown that people with lower vitamin E levels tend to have a higher rate of ischemic heart disease mortality and vice versa. One study found that people with the highest intake of vitamin E from dietary sources had less than half the risk of cardiac events when compared to those with the lowest intake. Other studies have shown that the use of vitamin E supplements has produced a 50% reduction in the progression of atheroma growth, a 63% decrease in coronary heart disease death, a 34% reduction in risk of cardiac events in women, a 77% decrease in the reoccurrence of non-fatal myocardial infarction, and a 39% decrease in risk of heart disease in men. Overall, the use of vitamin E supplements at any time was associated with a 47% decrease in heart disease related mortality.
The downside of the use of vitamin E is that large amounts have been associated with a possible increase in oxidation. In order to prevent oxidation of fats, the vitamin E itself must become oxidized. If all of the vitamin E in an LDL particle becomes oxidized, it is then able to cause oxidation of LDL cholesterol. A way to prevent this from happening is to make sure that there is enough of the antioxidant vitamin C available. Vitamin C is very effective at restoring oxidized vitamin E back to its non-oxidized, antioxidant form. For this reason, studies recommend that an increase in vitamin E intake be accompanied by an increase in vitamin C intake. Also, because of its ability to decrease platelet clumping and clot formation, supplemental vitamin E should not be used by those taking blood thinners unless they are being closely monitored by their doctor.
According to recently released National Academy of Sciences Dietary Reference Intake report, Americans are only consuming half the Recommended Daily Allowance (RDA) of 15 milligrams of vitamin E a day. A study published in the March 2005 Journal of the American Dietetic Association shows that enjoying a handful of almonds every day can do much to prevent Americans' vitamin E shortfall.
Researchers at Loma Linda University gave 16 healthy men and women (8 men, 8 women) three different diets for four weeks each: a control diet with no almonds, a low-almond diet and a high-almond diet. In the low- and high-almond diets, 10 percent and 20 percent of total calories, respectively, were replaced with almonds&madsh; the equivalent of one to two handfuls of almonds a day. Study participants took no dietary supplements before or during the study. After each four week diet, changes in their blood levels of alpha-tocopherol vitamin E and their cholesterol levels were evaluated.
Results showed that when 10 percent of the subjects' calories came from almonds, their blood levels of vitamin E increased 13.7%. When 20 percent of subjects' calories were supplied by almonds, their vitamin E levels increased 18.7%. In addition to increasing their blood levels of vitamin E, study participants also reduced their total cholesterol by 5%, and their LDL or "bad" cholesterol dropped nearly 7% percent when consuming the high-almond diet.
Almonds are a leading food source of vitamin E: a one-ounce handful provides 7.4 mg or about 50% percent of the RDA for this important antioxidant, plus health-protective monounsaturated fats, dietary fiber, protein and important minerals. So snack on a handful of almonds or add them to your daily meals. You'll significantly boost your vitamin E levels and improve your cholesterol profile, both of which promote your cardiovascular health.
One caveat: pass on highly salted almonds and those roasted at high temperatures. Too much sodium in the diet is a cardiovascular risk factor, and roasting nuts at high temperatures destroys their vitamin E and damages their healthy fats. To get the most benefit from your daily handful of almonds, choose organic nuts and eat them raw, or if you really enjoy roasted salted nuts, mist your almonds with Bragg's Liquid Aminos or a low sodium soy sauce, spread on a cookie sheet and bake at 170° until just toasted—15-20 minutes. Another added benefit: roasting your own almonds will also cut your cost for these roasted nuts by at least half.
Mustard greens, chard, turnip greens, and sunflower seeds are excellent sources of vitamin E. Click here for more food source of vitamin E.
Vitamin C is the primary water-soluble antioxidant found in the body. Although it is not found in LDL cholesterol particles because it is not fat-soluble, it does play a large role in the prevention of LDL oxidation. In addition to restoring antioxidant function to vitamin E, vitamin C also eliminates many free radicals produced by normal body metabolism, thus preventing them from affecting cholesterol.
Low levels of vitamin C have also been associated with higher levels of total cholesterol and LDL cholesterol and lower levels of HDL cholesterol. Vitamin C is required for the breakdown of cholesterol to bile in the liver and also for the uptake of LDL cholesterol into cells for normal use. Vitamin C use is therefore associated with a decrease in total and LDL cholesterol levels as well as an increase in HDL levels. These effects seem to be most pronounced in men and tend to take about six months of increased vitamin C intake to be significant.
Low vitamin C levels are associated with an increase in cholesterol deposition in the aorta, the main artery leaving the heart. Vitamin C has been shown to decrease the binding of monocytes to atheroma lesions, thereby reducing the rate of atheroma growth. It is especially beneficial in preventing the negative effects of smoking on the blood vessels and heart. Vitamin C also reduces the deactivation of NO and actually increases the production of NO, leading to decreased vessel spasm and increased vasodilation.
Excellent food sources of vitamin C include broccoli, parsley, green bell peppers, strawberries, cauliflower, lemons, romaine lettuce, mustard greens, Brussels sprouts, papaya, kale, snow peas, cabbage, spinach, kiwifruit, cantaloupe, oranges, grapefruit, tomatoes, chard, collard greens, raspberries, peppermint leaves, asparagus, celery, fennel bulb, pineapple, and watermelon.
Click here for more food source of vitamin C.
Bioflavonoids, which are chemical substances classified as pigments, help provide fruits and vegetables with their recognizable colors, and have many different effects in the body including antioxidant effects. A high intake of bioflavonoids, specifically those found in tea, onions, citrus fruits, red grape skins, and apples, has been associated with a significant decrease in risk of cardiovascular disease mortality. Although the exact mechanisms of bioflavonoids' actions are not fully understood at this point in time, their beneficial effects have been well documented.
Some concentrated food sources of bioflavonoids include red grapes, onions, apples, and citrus fruits.
Beta-carotene is another antioxidant found in foods. Although it is not found in high quantities in LDL cholesterol particles, it has been shown to prevent the oxidation of LDL cholesterol. Beta-carotene, like vitamin C, is also able to increase vessel dilation and reduce vessel spasm. One study has shown that patients with the lowest level of beta-carotene intake had almost twice the risk of having a myocardial infarction compared to those with the highest intake. The group of patients taking the highest intake of beta-carotene had about 1/3 the risk of fatal myocardial infarction and about 1/2 the risk of cardiovascular death as those in the group with the lowest intake.
Excellent food sources of beta-carotene include sweet potatoes, carrots, kale, winter squash, collard greens, chard, cantaloupe, mustard greens, romaine lettuce, spinach, parsley, cayenne pepper, peppermint leaves, Brussels sprouts, tomatoes, broccoli, asparagus, and apricots.
Monounsaturated fats are a unique type of fat found in particularly high quantities in olive oil. Studies have revealed that populations that follow the "Mediterranean" diet, which is high in vegetables and whole grains, and low in saturated fats, but relatively high in total fat due to a high intake of olive oil, tend to have fairly low rates of cardiovascular disease and its associated mortality. Based on studies of fat intake and heart disease in many countries, it would be expected that these populations would have high rates of heart disease because of the level of fat in their diets. However, the opposite is true.
Recent studies have shown that LDL cholesterol particles that contain monounsaturated fats, such as from olive oil, are much more resistant to oxidation that those that contain high levels of polyunsaturated fats, such as from other vegetable oils like safflower oil. In addition, the substitution of dietary saturated fats with monounsaturated fats has been shown to decrease total cholesterol by 13.4% and to decrease LDL cholesterol by 18%.
Relying only olive oil may cut your risk of coronary heart disease almost in half, show results from the CARDIO2000 case-control study, published in Clinical Cardiology (Kontogianni MD, Panagiotakos DB, et al.).
Conducted in Greece, and involving 700 men and 148 women with coronary heart disease, and 1078 age- and sex-matched healthy controls, this study looked not only at diet but also at alcohol intake, physical activity and smoking habits. Nutritional habits, including use of oils in daily cooking or preparation of food, was also evaluated.
Even after adjustments were made to account for a variety of other variables -- including body mass index, smoking, physical activity level, educational status, a family history of heart disease, high blood pressure, high cholesterol and diabetes -- exclusive use of olive oil was associated with a 47% lower likelihood of having coronary heart disease.
Consuming other fats or oils as well as olive oil, however, conferred no protection.
The researchers concluded, "Exclusive use of olive oil during food preparation seems to offer significant protection against coronary heart disease, irrespective of various clinical, lifestyle and other characteristics of the participants."
It's important to recognzie that benefits accrue from the use of monounsaturated fats to replace saturated fats and vegetable oils high in omega-6 fatty acids, such as corn oil. Adding olive oil onto a diet that is already high in omega-6 fats and saturated fats can have negative effects on heart disease progression and risk. Olive oil should instead be used to replace animal sources of fat and other vegetable oils. Even though olive oil is a relatively stable fat and is therefore recommended for cooking, it is important not to use olive oil for baking, broiling, or frying. Exposing it to very high temperatures for long periods of time in these fashions this may cause it to oxidize.
The best sources of monounsaturated fats include olive oil, high oleic safflower oil, high oleic sunflower oil, canola oil, grapeseed oil, and avocado.
Practical Tips:
Instead of serving butter, fill a small condiment dish with extra virgin olive oil for use on bread, rolls, potatoes or other vegetables. For even more flavor, try adding a few drops of balsamic vinegar or a sprinkling of your favorite spices to the olive oil.
To get the most health benefit and flavor from your olive oil, buy and store oil in opaque containers, and add olive oil to foods immediately after cooking.
In addition to its monounsaturated fats, the abundant polyphenols in extra virgin olive oil, which have anti-inflammatory, antioxidant and anticoagulant actions, contribute significantly to the oils well known cardiovascular benefits.
Virgin olive oil, a much richer source of polyphenols than refined olive or other refined oils, is the best vegetable oil for heart health, shows the results of the Eurolive study, published in the September 2006 Annals of Internal Medicine.
The 6 research center study, led by Maria-Isabel Covas of the Municipal Institute of Medical Research in Barcelona, assigned 200 healthy men from 5 European countries - Spain, Denmark, Finland, Italy and Germany — to one of three sequences of daily consumption of olive oil. The men replaced their normal dietary fats with olive oil (25 mL) containing either 2.7 (refined), 164 (virgin), or 366 (extra virgin) mg/kg of phenols for 3 weeks. This was followed by 2 weeks without any olive oil and then a cross-over to each of the other 2 remaining interventions.
Blood samples were taken before and after each intervention to measure blood sugar, total and HDL (good) cholesterol, triglycerides, free radical damage to cholesterol, and antioxidant levels.
The data revealed a linear increase in HDL (good) cholesterol levels as the phenolic content of the olive oil increased, with increases of 0.025, 0.032, and 0.045 mmol/L for the low, medium and high polyphenol-containing olive oils.
Oxidized LDL (the form in which LDL is involved in atherosclerosis) decreased linearly, dropping from 1.21 U/L , to -1.48 U/L , to -3.21 U/L for the low-, medium-, and high-polyphenol olive oil, respectively. And the ratio of total to HDL cholesterol, considered the most specific cholesterol-associated risk factor for cardiovascular disease, also decreased linearly as the phenolic content of the olive oil rose.
"Olive oil is more than a monounsaturated fat. Its phenolic content can also provide benefits for plasma lipid levels and oxidative damage," concluded the researchers.
A statement released by the Municipal Institute of Medical Research noted, 'This study represents a key piece for recommendations and contributes information with great repercussions for the community, especially in populations or countries where olive oil does not comprise the habitual oil of the diet."
Extra virgin olive oil—organic, if available—may cost a bit more than lesser quality oils, but the significant increase in cardiovascular benefits, not to mention richer flavor it provides, make it an extremely good investment in your health.
Earlier research conducted by Dr. Juan Ruano and colleagues at the Reina Sofia University Hospital, Cordoba, Spain, and published in the November 2005 issue of the Journal of the American College of Cardiology, provides additional reasons to choose extra virgin olive oil.
Reno and his team investigated the effects of virgin olive oil on endothelial function in 21 volunteers with high cholesterol levels.
The endothelium, although just a one-cell thick layer of flat cells that lines the inner wall of all blood vessels, may be the critical player in cardiovascular health. Among its many functions, the endothelium orchestrates the mechanics of blood flow, and regulates blood clot formation and the adhesion of immune cells to the blood vessel wall (one of the first steps in the formation of plaque).
Normally, after a meal, endothelial function is impaired for several hours. Blood vessels become less elastic, and blood levels of free radicals potentially harmful to cholesterol (lipoperoxides and 8-epi prostaglandin-F2) rise.
But when the subjects in this study ate a breakfast containing virgin olive oil with its normal high phenolic content (400 ppm), their endothelial function actually improved, blood levels of nitric oxide (a blood vessel-relaxing compound produced by the endothelium) increased significantly, and far fewer free radicals were present than would normally be seen after a meal.
When they ate the same breakfast containing the same type of virgin olive oil with its phenolic content reduced to 80 ppm, the beneficial effects were virtually absent, and concentrations of cholesterol-damaging free radicals increased. The results of this study underscore the importance of knowing how to select, store and serve your olive oil to maximize its polyphenol content. For all the information you need, see our Olive Oil How to Select and Store section.
Over the past five years, vitamin D has emerged as one of the key nutrient deficiencies contributing to risk of many chronic diseases, including colon cancer, breast cancer, ovarian cancer, type 2 diabetes, hypertension, and osteoporosis. To this impressive list can now be added heart disease - including atherosclerosis. Researchers have yet to determine the exact mechanisms connecting vitamin D with reduced risk of heart disease. Studies have already shown that vitamin D can lower inflammation by increasing levels of anti-inflammatory messengers like the cytokine named IL-10 (interleukin 10). Research has also shown that vitamin D can lower blood pressure, probably by inhibiting a regulatory system called the renin-angiotensin system. An analysis of vitamin D metabolism in 2006 has further suggested that vitamin D may be directly involved in cholesterol reduction. This analysis looked at the pharmacologic activity of certain cholesterol-lowering drugs called statin drugs. (The statin drugs, including lovastatin, pravastatin, and simvastain are some of the most widely-used prescription medicines for lowering cholesterol). It may turn out that these statin drugs act in the body by binding onto vitamin D receptors on cell membranes and mimicking the activity of vitamin D. Risk of atherosclerosis increases with age, and so does the need for vitamin D. Some studies suggest that it may be difficult to prevent the chronic diseases associated with vitamin D deficiency unless the Adequate Intake (AI) levels set by the National Academy of Sciences in 1997 be treated as minumum standards for vitamin D intake. Those levels are 5 micrograms of vitamin D daily for adults under 50 years of age, 10 micrograms for adults 51-70, and 15 micrograms for everyone above the age of 70.
Women's risk for cardiovascular disease increases after menopause, in part because levels of risk factors including homocysteine and excess body iron, tend to rise.
In this study (Hanson L, Engleman H, American Journal of Clinical Nutrition), researchers looked at the effect of soy protein, specifically soy's isoflavones and phytate, on CVD risk factors in 55 postmenopausal women. To do so, they randomly assigned the women to 1 of 4 soy protein (40 grams per day) groups: soy containing both its native phytate and native isoflavones, native phytate but low isoflavone, low phytate and native isoflavone, or low phytate and low isoflavone.
After just 6 weeks, women in the groups given soy protein with its native phytate had significant reductions in homocysteine and excess iron concentrations. Soy protein with native isoflavones had no effect.
Most interesting about this study is the fact that the phytate in soy, a compound which, because of its mineral-binding effects, has sometimes been considered problematic, that is responsible for some of the CVD-protective effects soy offers postmenopausal women. Once again, Mother Nature appears to have good reason for all the compounds found in whole foods.
Omega-3 fatty acids, a type of fat essential for normal body function, are used to make cell membranes throughout the body and immune system-related chemicals that help regulate inflammation. Omega-3 fatty acids are found in fairly high quantities in cold water fish, which is one reason why populations with a high fish intake have much lower rates of cardiovascular disease and related mortality compared to those with low fish intake.
Omega-3 fatty acids have been shown to decrease the proliferation of smooth muscle cells, decrease the movement of macrophages into the vessel wall, increase the removal of LDL cholesterol from the bloodstream, decrease platelet aggregation and thrombus formation following endothelial injury, increase vasodilation by enhancing the effects of NO, and increase thrombus (blood clot) breakdown.
After a blood clot has caused a heart attack, omega-3 fatty acids have been shown to increase the rate of clot breakdown, reducing the damage to the heart's cells caused by lack of blood flow. Omega-3s also decrease the attraction of immune cells to the site of damage, thereby reducing the additional damage caused by these cells, and reducing the risk of ventricular fibrillation, or cardiac arrest, after a heart attack.
Consuming fish or fish oils as little as once a week has been shown to cause a 50% reduction in cardiac arrest, presumably due to the ability of omega-3 fats to prevent ventricular arrhythmias. In general, people with higher levels of omega-3 fats in their red blood cells have a 70% decreased risk of cardiac arrest than those with lower levels. The use of fish oil was shown in one study to decrease mortality by 29% in men who had already had one acute myocardial infarction.
By decreasing the attraction of immune system cells, omega-3 fats can also prevent the high levels of free radicals that these cells produce, possibly leading to decreased oxidation of LDL cholesterol. An increased intake of omega-3 fats combined with a low saturated fat diet can produce a 28% decrease in total cholesterol and a 30% reduction in LDL cholesterol.
Just two servings of omega-3-rich fish a week can also lower triglycerides—a serious risk factor for diabetes as well as cardiovascular disease.
Triglycerides are a form in which fat is carried in your bloodstream. In normal amounts, triglycerides are important for good health because they serve as a major source of energy. High levels of triglycerides, however, are associated with high total cholesterol, high LDL (bad) cholesterol and low HDL (good) cholesterol), and therefore, with an increased risk of cardiovascular disease.
In addition, high triglycerides are often found along with a group of other disease risk factors that has been labeled metabolic syndrome, a condition known to increase risk of not only heart disease, but diabetes and stroke. (Metabolic syndrome is the combined presence of high triglycerides, increased blood pressure, high blood sugar, excess weight, and low HDL (good) cholesterol.)
| Triglyceride Levels | |
|---|---|
| Less than 150 mg/dL | Normal |
| 150-199 mg/dL | Borderline-high |
| 200-499 mg/dL | High |
| 500 mg/dL | Very High |
*Note: Triglycerides are most accurately measured after an 8-12 hour fast.
In this 6-month study involving 142 overweight men and women with high triglycerides, subjects were divided into 5 groups, one of which served as a control group, 2 of which ate 2 servings of fish high in omega-3s while also replacing their normal household fats with fat high in sunflower (Group 1) or canola oil made from rapeseed (Group 2), and 2 of which ate 2 weekly servings of white fish while also replacing their normal household fats with ones high in sunflower (Group 3) or canola oil made from rapeseed (Group 4).
Canola oil also provides some omega-3 fats, with an omega-6:omega-3 ratio of 2:1, while sunflower oil contains omega-6, but no omega-3 fats.
At the end of the study, triglyceride levels had dropped 6.6% in the omega-3-rich fish groups combined. Triglycerides dropped most—10.4%—in those consuming omega-3-rich fish and canola oil. In those eating omega-3-rich fish and sunflower oil, triglycerides dropped 2.8%. Bottomline: A healthy way of eating that incorporates at least 2 weekly servings of fish and other food sources of omega-3 fats, such as flaxseed or canola oil, may significantly lower triglyceride levels. Replacing normal household fats with flaxseed oil, in which the ratio of omega-6:omega:3 fats is 1:4, might result in an even larger drop in triglyceride levels.
It is important when increasing omega-3 fat intake to also decrease saturated fat intake. Simply adding fish or fish oil to a diet high in saturated fats from animal sources or polyunsaturated fats from vegetable oils generally does not result in the benefits listed above and may actually cause harm because of the additional fat intake.
Greek researchers looked at the effect on systolic and diastolic blood pressure of a three-month trial during which 59 middle-aged men used either flaxseed or safflower oil in their daily diet.
Flaxseed oil is rich in the omega-3 fat, alpha-linolenic acid (ALA), which the body can metabolize into the cardioprotective long-chain omega-3 fatty acids, DHA and EPA, while safflower oil is a concentrated source of the omega-6 fat, linoleic acid (LA). The men received flaxseed oil supplying 8 grams of ALA daily or safflower oil providing 11 grams of LA per day.
At the conclusion of the 12-week study, both systolic and diastolic blood pressure was significantly lower in the men using the omega-3-rich flaxseed oil.
One possible explanation for this result is the anti-inflammatory effects of omega-3 fats. Both omega-6 and omega-3 fats are essential fatty acids: we need both types of fats to be healthy and must derive them from our food. Omega-6 fats, however, tend to promote excessive inflammation when not balanced by sufficient amounts of omega-3 fats in the diet.
Most nutrition experts believe that a health-promoting ratio of omega-6 to omega-3 fats is no higher than 4:1, and many believe the optimal ratio is 2:1. The typical American diet, however, delivers almost 10 times as much omega-6 as omega-3 fatty acids.
Practical Tip: Numerous studies have shown heart-protective benefits from decreasing the ratio of omega-6 to omega-3 fats in the diet. To improve your omega 6:omega to omega-3 ratio increase your consumption of foods rich in omega-3s, such as flaxseed oil, canola oil, walnuts, and cold-water fish like wild salmon. And decrease your consumption of foods rich in omega-6 fats, such as safflower oil, corn oil, peanut oil, butter and the fats found in meats.
Excellent food sources of omega-3 fatty acids include salmon, flax seeds and walnuts.
Click here for more food sources of omega-3 fatty acids.
Zinc is an essential mineral found in a variety of whole foods. In addition to acting as an antioxidant, zinc has other functions that can decrease the progression of atherosclerosis. Zinc is needed for the proper function of endothelial cells and helps to prevent the endothelial damage caused by oxidized LDL cholesterol and other oxidized fats. Endothelial membranes low in zinc are much more prone to injury.
Zinc can also prevent the increase in adhesion molecules on damaged endothelial cell membranes, thereby preventing the increased binding of immune cells which contributes to atheroma formation and growth.
Zinc has been shown to prevent some of the damage to heart muscle cells after a myocardial infarction by decreasing the free radicals produced by the immune cells that enter the area after the thrombus has broken down.
Zinc levels in general tend to be low in atherosclerosis patients. Increasing dietary intake of zinc with zinc-rich foods can help to prevent or reverse low zinc levels.
Calf liver, spinach and crimini mushrooms are very good sources of zinc.
Click here for more food sources of zinc.
Magnesium, which is a cofactor in more than 300 enzymatic reactions in the body, is a mineral essential for normal cell metabolism and function. Low dietary levels of magnesium are associated with increased rates of hypertension, heart arrhythmias, ischemic heart disease, and sudden cardiac death. Low levels of magnesium have been found in the hearts and blood vessels of patients with angina, coronary artery disease, and also in patients who have died of ischemic heart disease related sudden death.
Higher levels of magnesium in tap water is associated with lower rates of ischemic heart disease mortality. For example, more magnesium is found in the soil and drinking water in the Western United States than in the Eastern United States. More cardiovascular disease and associated mortality is found in the East.
Low magnesium levels can occur due to low dietary intake of magnesium or increased excretion of magnesium. Increased excretion tends to be found in patients with diabetes, high alcohol intake, certain gastrointestinal problems, high sodium intake, and in people taking diuretic medication.
Low magnesium levels are related to decreased function of endothelial cells including increased susceptibility to damage and lesion formation; increased calcification of atheromas; decreased collagen breakdown, leading to increased collagen build up in atheromas; elevated lipoprotein and LDL levels; low HDL levels; decreased normal cellular uptake and use of cholesterol; increased cholesterol build up in blood vessel walls; and increased platelet clumping and clot formation.
Increased intake of magnesium has been shown to result in improved function of heart cells in general due to improved metabolism. In addition, magnesium decreases vessel spasm and increases vasodilation. Magnesium can decrease the formation and growth of atheromas, even in patients with high cholesterol levels. In general, increasing dietary magnesium intake may decrease the progression of atherosclerosis as well as helping to prevent the consequences of the condition.
Chard and spinach are two excellent food sources of magnesium.
Click here for more food sources of magnesium.
Potassium is found in every cell of the body and is needed for normal function, especially of the cells of the heart. Although blood potassium levels are generally assumed to be kept at fairly stable levels in the body at all times, recent research has shown that these levels can be influenced somewhat.
Increasing the level of dietary potassium while also decreasing the level of dietary sodium can actually cause blood potassium levels to increase slightly. Although the increase is small, it has been associated with some fairly significant effects as far as cardiovascular disease is concerned.
Higher blood levels of potassium have been shown to decrease the amount of free radicals produced by damaged endothelial cells and activated monocytes and macrophages. Higher levels have also been shown to decrease the proliferation of smooth muscle cells and to decrease platelet clumping and thrombus formation at the sites of endothelial damage. In addition, potassium has been shown to protect against the formation of vascular lesions.
When increasing dietary potassium, it is important to also decrease dietary sodium intake for these positive effects to occur.
Chard, crimini mushrooms, and spinach are some excellent food sources of potassium.
Click here for more food sources of potassium.
Onions and garlic have been recognized as protective against cardiovascular disease for a long time. In studies, when garlic and onion oil were consumed along with butter, the combination prevented the rise in blood cholesterol levels that typically occurs after butter, which is high in cholesterol and saturated fat, is consumed. Garlic and onion oil was found to contain compoments that also decreased blood clotting and increased thrombus breakdown potential.
Garlic intake has also been shown to decrease the proliferation of cells in atheromas and to decrease the amount of cholesterol found in these cells. In research studies, garlic use has been found to decrease the amount of cholesterol taken up by smooth muscle cells in atherosclerosis patients.
Research presented at the 6th Annual Conference on Arteriosclerosis, Thrombosis and Vascular Biology held by the American Heart Association April 29, 2005 in Washington, D.C., suggests that garlic can help prevent and potentially reverse atherosclerotic plaque formation.
The laboratory studies, conducted by well-known German scientist Professor Günter Siegel, M.D., from the University of Medicine in Berlin, Germany, found that powdered garlic (Kwai® garlic) reduced the formation of nanoplaque (the first building blocks of atherosclerotic plaque) by up to 40% and reduced the size of the nanoplaque that did form by up to 20%.
Dr. Siegel s research shows that garlic acts in a manner similar to HDL ("good") cholesterol, which prevents the build-up of nanoplaques by hindering the docking of LDL ("bad" cholesterol) to its receptor sites in blood vessels or existing plaques.
Both garlic and HDL were able to reduce plaque formation and size within 30 minutes of incubation in these experiments. Existing plaques were dissolved by up to 25% within 15 minutes after the garlic was introduced, indicating a reversal of existing problems related to build-up of arterial plaque. In addition, calcification of the cholesterol docking sites in the arteries was reduced by up to 50% in the presence of the garlic extracts. (Calcium, although a vital mineral for bone formation and other essential physiological processes, is also one of the key factors involved in the formation of plaque.)
Adding liberal amounts of garlic and onions to food may therefore improve blood cholesterol levels and reduce the progression of atherosclerosis.
Best Food Sources of the Heart-Protective Components in Onions and Garlic: Fresh, raw garlic and onions contain higher amounts of beneficial compounds.
Note - Studies seem to indicate that the most beneficial components of garlic and onion are also the ones that tend to break down over time. For this reason, it is recommended that people use fresh garlic and onions, instead of dried or powdered, in their foods in order to get the best effects.
Red chili peppers, such as cayenne, have been shown to reduce blood cholesterol, triglyceride levels, and platelet aggregation, while increasing the body's ability to dissolve fibrin, a substance integral to the formation of blood clots. Cultures where hot pepper is used liberally have a much lower rate of heart attack, stroke and pulmonary embolism.
Spicing your meals with chili peppers may also protect the fats in your blood from damage by free radicals—a first step in the development of atherosclerosis. In a randomized, crossover study involving 27 healthy subjects (14 women, 13 men), eating freshly chopped chili was found to increase the resistance of blood fats, such as cholesterol and triglycerides, to oxidation (free radical injury).
Subjects were randomly divided into 2 groups. For 4 weeks, half the subjects ate a freshly chopped chili blend (30 grams/day, about 1 ounce), consisting of 55% cayenne, while the other half consumed a bland diet (no chili). After 4 weeks, the groups were crossed over for another 4 weeks. During the intervention periods, consumption of other spices such as cinnamon, ginger, garlic, and mustard was restricted. Blood samples were obtained at the beginning of the study and after each dietary period.
After eating the chili-containing diet, the rate of oxidation (free radical damage to cholesterol and triglycerides) was significantly lower in both men and women than that seen after eating the bland diet.
In addition, after eating the chili-spiced diet, women had a longer lag time before any damage to cholesterol was seen compared to the lag time seen after eating the bland diet. In men, the chili-diet also lowered resting heart rate and increased the amount of blood reaching the heart.
These three B vitamins and betaine are all needed to prevent the buildup of homocysteine, which is directly damaging to blood vessel walls. As mentioned above, homocysteine is an independent risk factor for heart disease development and mortality. Homocysteine is formed as an intermediate product during an important process called the methylation cycle that occurs in virtually all our cells. Betaine (along with the B vitamins, folic acid, vitamin B12, B6; are all required for methylation to proceed properly, converting homocysteine back to methionine through a number of steps instead of log jamming after homocysteine is formed.
Eggs are a concentrated source of betaine.
In some people, homocysteine levels become elevated because of an inherited mutation in one or more of the genes that produce the enzymes for these reactions. These people typically require more of B6, B12 and folate than others in the population to keep their homocysteine levels low. In others, elevated levels are due to a deficient dietary intake of these vitamins. In either case, increasing consumption of foods containing B12, B6 and folic acid is recommended to decrease homocysteine levels and reduce cardiovascular disease risk.
Folate is needed for the conversion of homocysteine back into methionine. Studies have shown that low folate levels are associated with an increased risk of coronary heart disease mortality. Increased intake of folate has been shown to decrease homocysteine levels by 25-50%.
Excellent food sources of folic acid include romaine lettuce, spinach, asparagus, turnip greens, mustard greens, calf's liver, parsley, collard greens, broccoli, cauliflower, beets, and lentils.
Click here for more food sources of folic acid.
The absorption of vitamin B12 requires a certain substance called intrinsic factor that is produced by the stomach. Elderly persons and persons with stomach or digestive problems are especially prone to vitamin B12 deficiency as they may not be producing enough intrinsic factor to absorb the vitamin B12 they take in. Low dietary intake of vitamin B12 may also produce a state of deficiency.
Vitamin B12 deficiency may also produce neurological problems, such as problems with sensation in the limbs. Since high folate consumption can mask the symptoms of vitamin B12 deficiency, people who increase their folate intake should also increase their vitamin B12 intake. Increasing vitamin B12 intake has been shown to produce a 10-15% decrease in homocysteine levels. The effect of vitamin B12 on elevated homocysteine levels is most pronounced when the elevated levels are due in part to low vitamin B12 levels.
Excellent food sources of vitamin B12 include calf liver and snapper.
Click here for more food sources of vitamin B12.
Low levels of vitamin B6 in the body are strongly associated with elevated homocysteine levels. Low vitamin B6 levels are also associated with a type of homocysteine problem only seen in some patients after they are challenged with methionine. In these patients, homocysteine levels appear normal, but when they are given methionine as a test, their homocysteine levels rise quickly and take a very long time to come back down. These people also have an increased risk of cardiovascular disease. Vitamin B6 use can restore the results of the methionine challenge test, and therefore homocysteine metabolism, to normal 56% of the time, and produce great improvements in an additional 20% of cases.
Some excellent food sources of vitamin B6 include bell peppers, turnip greens and spinach. Click here for more food sources of vitamin B6.
Note: These nutrients are most helpful in patients with borderline high blood pressure. Patients with extremely high blood pressure or who are taking medication for hypertension should be closely monitored by their physician.
Potassium is an essential mineral needed for the proper function of every cell in the body. In particular, it is needed for proper heart and blood vessel function. In people who eat more "primitive" diets, which are high in fruits, vegetables, and whole grains and low in processed foods, potassium intake levels are high, and rates of cardiovascular disease and hypertension tend to be very low. The fact that people consuming "primitive" diets have high levels of potassium intake compared to sodium intake is not surprising since most fruits and vegetables have a ratio of potassium to sodium of 50:1.
Diets that are high in potassium are especially good at lowering blood pressure if they are also low in sodium. In the U.S., intake of sodium in the form of salt added to processed foods tends to be very high, while intake of potassium, found in high amounts in fruits and vegetables, tends to be very low. Compared to societies where potassium intake is high and sodium intake is low, the incidence of hypertension in the U.S. is much higher. Higher potassium intake, especially when sodium intake is fairly low, is not only associated with decreased blood pressure, but with decreased risk of stroke due to cardiovascular disease.
Chard, crimini mushrooms, and spinach are some excellent food sources of potassium. Click here for more food sources of potassium.
Magnesium is another essential mineral that is needed for basic cell metabolism and function. Low levels of magnesium are often observed in patients with hypertension, especially the form of hypertension that is exacerbated by high sodium intake. As with potassium, magnesium levels tend to be lower when the diet is high in sodium.
Red blood cell levels of magnesium are strongly related to diastolic blood pressure. Diastolic blood pressure is the second reading, which is taken after the heart has pumped and shows the residual pressure left in the arteries. When red blood cell magnesium levels are lower, diastolic blood pressure tends to be higher. When levels are higher, diastolic blood pressure tends to be lower.
Hypertension also tends to lower phosphate levels, which then can make the hypertension worse. Increasing magnesium intake has been shown to restore phosphate levels to normal. In addition, increased magnesium intake has been shown to directly decrease blood pressure levels.
Chard and spinach are two excellent food sources of magnesium.
Click here for more food sources of magnesium.
Taurine is an amino acid found in high amounts in fish protein. Supplementation of the diet with taurine in one study showed a decrease in both systolic and diastolic blood pressures in approximately 65% of patients studied. To attain the amount of taurine used in the study, you would need to consume fish at least five times a week.
Best Sources of Taurine: Fish - especially cold water fish like salmon and cod.
When cells are resistant to insulin, high levels build up in the blood stream and are damaging to blood vessel walls. Insulin resistance is a primary characteristic of Type II (also called Adult-onset or Non-insulin Dependent) Diabetes. For detailed information on nutrients that decrease insulin resistance, please refer to Non-Insulin Dependent Diabetes.
The following nutrients or food substances, when consumed in large amounts, can contribute to the development and progression of atherosclerosis. Limiting intake of these lowers risk of cardiovascular disease mortality.
Results of the CARDIO2000 case-control study indicate that frequent red meat consumption significantly increases risk of "acute coronary syndrome," a label which includes greatly increased risk of unstable angina, plaque rupture, blood clot formation and heart attack. (Kontogianni MD, Panagiotakos DB, et al., Eur J Clin Nutr)
In this research, involving 848 patients and 1078 healthy age- and sex-matched controls, eating more than 8 servings of red meat a month was associated with 52% increased risk of a "cardiac event," e.g., cardiac arrest and sudden death.
Eating white meat more than 12 times a month increased likelihood of having a cardiac event by 18%.
Study participants who ate 8 or more portions red meat or 12 or more portions of white meat each month had 4.9 and 3.7 higher odds of having a heart attack, respectively, compared to those with low meat intake (less than 4 portions of red meat and less than 8 portions of white meat per month, respectively). Practical Tip: Limit your consumption of red meat to once a week and white meat to twice a week. Enjoy more meals featuring fish, eggs, and whole grain/legume combinations. Let our Recipe Assistant help you find quick, easy and delicious ideas for meat-free meals.
As much as 80% of all elevated cholesterol levels are thought to be due to excessive amounts of cholesterol and saturated fat in the diet. Intake of saturated fats and cholesterol in the U.S. are fairly high, especially compared to populations with much lower rates of cardiovascular disease and associated mortality.
Diets low in cholesterol result in less dietary cholesterol being available for absorption into the blood stream.
Diets low in saturated fats can decrease cholesterol by reducing the amount of saturated fat available for conversion into cholesterol, and also by increasing the uptake and use of LDL cholesterol by cells of the body.
Saturated fats and cholesterol are found primarily in animal products such as meat, dairy products including milk and cheese, and eggs. The saturated fat contain in eggs, however, may not be as problematic for risk of heart disease as the saturated fat contained in other aminal products, since it is largely a different kind of saturated fat (made up of building blocks called short chain fatty acids).
Consumption of large amounts of meat and dairy products in childhood is now being associated with the beginning stages and increased risk of atherosclerosis in the future. For example, high cholesterol levels in people under 30 years of age are now believed to be strongly predictive of an increased risk for atherosclerosis later in life.
A number of studies support the reduction of cholesterol intake to less than 300 mg per day and reducing the amount of saturated fat in the diet to less than 10% of total calories. Unfortunately, studies show that simply cutting back on cholesterol and saturated fat may not be enough to have a big impact on cholesterol levels. Diets low in saturated fats and cholesterol tend to lower total cholesterol levels by about 5-10% and LDL cholesterol by about 7-9%. One study comments that those who attempt to make these changes generally only lower their cholesterol levels by 3-4%. A much greater reduction in cholesterol levels results when intake of saturated fat and cholesterol is minimized while intake of soluble fiber and fish is increased.
Iron is a normal component of red blood cells that allows them to carry oxygen to the rest of the cells of the body. Too much iron, however, can be problematic, especially when that iron floats freely inside cells. Studies have shown a correlation between higher levels of iron stores and an increased rate of cardiovascular mortality.
Some researchers propose that menstruating women's lower levels of stored iron may explain why they have a much lower rate of cardiovascular disease compared to men and postmenopausal women. When iron loss from menstruation stops after menopause, iron levels can build up in women consuming an iron-rich diet, increasing their risk of heart disease.
Some studies have shown that regular blood donation may decrease the risk of myocardial infarction by as much as 86% in men. The negative effects of high iron stores and high amounts of free iron inside of the cells seem to occur most frequently in patients with high cholesterol or LDL cholesterol levels. In one study done in men, the risk for myocardial infarction in men with the highest iron stores was more than double, while men with high iron stores and high cholesterol levels had four times the risk. Those with high iron stores and low cholesterol levels showed only a slight increase in risk.
It is believed that initial injury to the endothelial wall causes iron to be released from iron stores. Once released, this iron becomes highly reactive and is able to cause the oxidation of LDL cholesterol. Iron's oxidation of LDL cholesterol leads to the formation and progression of atheromas.The main source of iron in the diet is meat, especially red meat, which contains high levels of a type of iron called heme iron. In fact, one study found that men who consumed meat 6 times a week had a 60% increase in risk of fatal coronary artery disease compared to men who ate meat less than once a week.
Fortunately, the relationship between dietary iron intake and cardiovascular risk does not appear to apply to non-heme iron, which is the type found in certain vegetables. Elevated iron store levels can be decreased through blood donation as well as exercise, which can reduce iron stores through sweating, increased muscle mass, and red blood cell metabolism.
Fatty acids are found in two main forms: cis and trans. The cis form is the form found most commonly in natural vegetable oils and animal products. However, certain conditions, such as heating oils for a long period of time or the process of hydrogenation, which turns liquid oils into a more solid form to create shelf-stable products such as margarine, creates fatty acids in the trans form. The digestion of fats in certain farm animals can also produce trans fats. Trans fatty acids, therefore, are found in a number of foods such as margarine, baked goods, and fried foods, particularly those from fast food restaurants, where the same oil is maintained at a high temperature for long periods and used repeatedly for frying. Trans fat also occurs naturally (in much smaller amounts) in most animal foods.
Recent studies have shown that trans fats are very detrimental to the body and increase the risk and progression of atherosclerosis even more than saturated fats. Many studies have shown a correlation between high levels of trans fatty acid intake and increased risk for cardiovascular disease and associated mortality. One study showed that the risk of fatal myocardial infarction between those in the group with the highest trans fat consumption level was more than twice that of the group with the lowest consumption level.
Although trans fatty acids do not raise total cholesterol and LDL cholesterol levels as much as saturated fats do, they have been shown to raise LDL levels higher than other types of oils. In addition, trans fats also have been shown to decrease HDL levels and raise lipoprotein a levels significantly. The increases in lipoprotein a levels are estimated to result in a 27% increase in risk of coronary blood clot formation.
Products containing hydrogenated oil or trans fats should be eliminated from the diet.
The recommended diet to help prevent, slow the progression of, and possibly even reverse atherosclerosis and heart disease is low in saturated fats, cholesterol, trans-fats, and processed foods, and high in whole foods. According to current medical research, the most important dietary actions you can take to reduce your risk of atherosclerosis and heart disease are:
Consume a healthy foods diet high in:
The importance of fruits and vegetables to cardiovascular health is underscorerd by a recent analysis of data gathered from the Danish Diet, Cancer and Health study, which included 54,506 men and women over a four year period. The results, published July 2003, showed that those who ate the most fruits and vegetables (an average of 23 ounces per day) had a 28% lower risk of ischemic stroke compared to those who ate the least (an average of 5 ounces a day). The benefits of eating fresh fruits were even higher. Those who consumed the most fruits had a 40% lower risk of stroke compared to those who ate the least.
New research continues to show the link between a healthy way of eating rich in fruits and vegetables and a greatly lower risk of cardiovascular disease. A meta-analysis of 9 studies involving more than 220,000 people, published in the October, 2006 issue of the Journal of Nutrition found that risk of coronary heart disease (CHD) drops as consumption of vegetables and fruit increases.
French researchers looked at studies including 91,379 men, 129,701 women and 5,007 heart attacks occurring over a 5 to 19 year period. Six studies reported an association between fruit and vegetable intake and coronary heart disease risk, six reported data for fruit intake and heart disease, and seven reported on the association between vegetable intake and heart disease risk.
Together, data from all the studies revealed a 4% drop in the risk of fatal and nonfatal heart attack, coronary death and the incidence of coronary heart disease for each additional serving of fruit and vegetables consumed daily.
Greater vegetable intake alone was linked to a 5% reduction in risk of CHD, while data on just fruit consumption showed a reduction in risk of 7%.
Each additional daily portion of vegetables consumed conferred a 26% decrease in risk of coronary death. Although the healthier lifestyle more typical among those who eat fruit and vegetables may contribute to the effects seen in this meta-analysis, the authors concluded that the preponderance of the evidence presented supports the finding that eating more fruit and vegetables lowers risk of coronary heart disease.
Oats, via their high fiber content, are already known to help remove cholesterol from the digestive system that would otherwise end up in the bloodstream. Now, the latest research suggests they may have another cardio-protective mechanism.
Antioxidant compounds unique to oats, called avenanthramides, help prevent free radicals from damaging LDL cholesterol, thus reducing the risk of cardiovascular disease, suggests a study conducted at Tufts University and published in the June 2004 issue of The Journal of Nutrition.
In this study, hamsters were fed saline containing 0.25 grams of phenol-rich oat bran, after which blood samples were taken at intervals from 20 to 120 minutes. After 40 minutes, blood concentrations of avenanthramides had peaked, showing these compounds were bioavailable (able to be absorbed).
Next, the researchers tested the antioxidant ability of avenanthramides to protect LDL cholesterol against oxidation (free radical damage) induced by copper. Not only did the avenanthramides increase the amount of time before LDL became oxidized, but when vitamin C was added, the oat phenols interacted synergistically with the vitamin, extending the time during which LDL was protected from 137 to 216 minutes.
In another study also conducted at Tufts and published in the July 2004 issue of Atherosclerosis, researchers exposed human arterial wall cells to purified avenenthramides from oats for 24 hours, and found that these oat phenols significantly suppressed the production of several types of molecules involved in the attachment of monocytes (immune cells in the bloodstream) to the arterial wall—the first step in the development of atherosclerosis.
Oat avenanthamides suppressed production of ICAM-1 (intracellular adhesion molecule-1) and VCAM-1 (vascular adhesion molecule-1), E-selectin, and the secretion of pro-inflammatory cytokines KL-6, chemokines IL-8 and protein MCP-1 (monocyte chemoattractant protein). Our advice: Cut an orange in quarters or pour yourself a glass of orange juice to enjoy along with your oatmeal. If you prefer some other grain for your breakfast cereal, top it with a heaping spoonful of oat bran.
Eating a serving of whole grains at least 6 times each week is a good idea, especially for postmenopausal women with high cholesterol, high blood pressure or other signs of cardiovascular disease (CAD).
A 3-year prospective study of 229 postmenopausal women with CAD, published in the July 2005 issue of the American Heart Journal, shows that those eating at least 6 servings of whole grains each week experienced both:
The women's intake of fiber from fruits, vegetables and refined grains was not associated with a lessening in CAD progression.
The 2005 Dietary Guidelines for Americans recommends at least 3 servings of whole-grain foods each day, but experts say most Americans eat less than a single serving. Don't be part of this majority!
For delicious ideas that can help you enjoy whole grains as a daily part of your "Healthiest Way of Eating," click barley, buckwheat, corn, millet, quinoa, brown rice, rye, spelt, whole wheat.
Two studies recently published in the American Journal of Clinical Nutrition further support the importance of eating whole grains to lower risk of not only heart disease, but metabolic syndrome and diabetes.
Older adults who ate 3 daily servings of whole grains were significantly less likely to develop metabolic syndrome or to die from heart disease than those eating refined grains, according to research conducted at the ARS Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts and published in the January 2006 issue of the American Journal of Clinical Nutrition.
Study findings were derived from three-day food records and blood tests done between 1981 and 1984 on 535 healthy men and women, aged 60-98 years, who were then followed for 12-15 years.
When sorted into groups according to the amount of whole-grain foods they ate, those eating the most—an average of about 2.9 servings a day—had significantly fewer metabolic syndrome risk factors and less risk of dying from heart disease than those in the group with the lowest intake of whole grains.
In contrast, eating refined grains was associated with higher fasting blood sugar levels, and a significantly higher prevalence of metabolic syndrome, and increased risk of death from cardiovascular disease.
Metabolic syndrome has become increasingly common in the United States with an estimated more than 50 million Americans affected by this condition, which is characterized by:
People with metabolic syndrome are at increased risk not only for coronary heart disease and other diseases related to plaque buildup in artery walls (e.g., stroke and peripheral vascular disease), but also type 2 diabetes.
In a second study published in the February 2006 issue of the American Journal of Clinical Nutrition, researchers at the Harvard School of Public Health evaluated 938 healthy men and women and found that those eating the most whole grains had the lowest blood levels of homocysteine (an amino acid that can damage the inner lining of the arteries and is a significant risk factor for cardiovascular disease), as well as better lipid profiles (less triglycerides, total and LDL cholesterol, and more HDL cholesterol), and lower blood levels of compounds whose elevation is associated with poor blood sugar control (fasting insulin, hemoglobin A-1c, C-peptide, and leptin).
Whole grains include whole wheat, breads, pasta, cereals and crackers made from whole wheat flour, brown rice, barley, oats, rye, spelt and quinoa. Refined grains include the wheat flour (also listed as unbleached wheat flour) used in the majority of commercially prepared breads, pasta, crackers, cookies, etc., sold in the United States, white rice and instant oatmeal.
While most Americans currently eat less than one daily serving of a whole-grain food, after their study of the effects of whole grains on older adults, the Tufts' researchers urge Americans of all ages to increase the amount of whole grains they eat to at least three servings a day.
For heart-healthy protein sources, depend on cold water fish, legumes, and soy products:
Soy foods such as tofu, tempeh, soy miso, and soymilk, should be eaten several times per week as a replacement for animal protein sources high in saturated fat such as dairy products and red meats.
Cold water fish, such as salmon and cod, should be eaten as often as 4-5 times per week since they not only provide excellent protein, but are rich in omega-3 essential fatty acids.
Legumes, which are rich in fiber, protein and minerals should also be dietary mainstays.
Fat-free cooking is recommended. Add fats after food is removed from the heat for flavor. If you do choose to cook with fat, cook at the lowest temperature and for the shortest time possible. Extra virgin olive oil or grapeseed oil are the best choices as these oils are high in monounsaturated fats, the fats most resistant to damage when heated.
Studies in weight-stable persons have shown that a diet including a moderate amount of fat results in lower blood levels of triglycerides and higher levels of beneficial HDL cholesterol than a low-fat diet. Now a new study suggests that a weight-loss diet high in monounsaturated fat and moderate in total fat may be more heart-healthy than one that's low in fat.
In this new study, published in the February 2004 issue of the American Journal of Clinical Nutrition and funded by the Peanut Institute, 53 overweight and obese men and women were randomly assigned to follow weight-loss diets for that were either very low in fat (18% of calories from fat) or moderate in fat (33% fat, with half the fat from peanut products). Participants consumed the weight-loss diet for six weeks, after which they followed a weight maintenance diet for an additional four weeks.
After the six week weight-loss period, both groups had lost about 15 pounds and lowered their levels of potentially harmful LDL. However, while those on the moderate fat diet kept their protective HDL cholesterol at the same level, thus significantly improving their ratio of HDL:LDL, those on the low-fat diet saw their HDL cholesterol drop by 12%, so their ratio of HDL:LDL did not improve —offsetting some of the heart benefits. In addition, during four weeks of weight maintenance, HDLs remained high in the moderate-fat group, who also further lowered their triglyceride levels, while triglyceride levels rebounded in those on the low-fat diet. (High triglycerides are a problem because they promote fat absorption in the artery wall.)
The message: moderate consumption of healthy monounsaturated fats, such as are found in olive oil and nuts, e.g., peanuts, appears to lessen risk of cardiovascular disease more than a low-fat diet. We'd add that the moderate fat diet is easier to follow since a little healthy fat adds satiety and a lot of flavor to your meals.
For salad dressings, olive oil and flaxseed oil (which is high in omega-3 essential fats) are the most heart-healthy choices. Flaxseed oil is easily damaged by light and heat, so it should always be refrigerated and never used in cooking.
While you may have become accustomed to thinking about nuts as too high in fat be part of a heart protective diet, this food group has been shown to lower risk of cardiovascular disease and heart attack—even in persons who are at higher risk of heart problems like individuals diagnosed with type 2 diabetes. Here are some of the study results on specific nuts and their heart-supporting properties.
Nuts are another source of cardio-protective fats. A study conducted at the Lipid Clinic in Barcelona, Spain, and published Circulation (Ros E, Nunez I, et al.) suggests that walnuts protect the heart by doing much more than just lowering cholesterol.
For four weeks, 21 men and women with high cholesterol followed either a regular, low-calorie Mediterranean diet or one in which walnuts were substituted for about one-third of the calories supplied by olives, olive and other monounsaturated fats in the Mediterranean diet. Then, for a second four weeks, they switched over to the diet they had not yet been on.
Not only did the walnut diet significantly reduce total cholesterol (a drop that ranged from 4.4 to 7.4%) and LDL (bad) cholesterol (a drop ranging from 6.4 to 10%), but walnuts were also found to increase the elasticity of the arteries by 64%, and to reduce levels of vascular cell adhesion molecules, a key player in the development of atherosclerosis (hardening of the arteries).
The researchers found that the drop in cholesterol correlated with increases in blood levels of alpha-linolenic acid, a key essential fatty acid from which omega 3 fats can be derived, and gamma-tocopherol, a form of vitamin E. Walnuts are uniquely rich in both of these nutrients, which have shown heart protective benefits in other studies.
The Food and Drug Administration has recently cleared the health claim that "eating 1.5 ounces per day of walnuts as part of a diet low in saturated fat and cholesterol may reduce the risk of heart disease."
"This is the first time a whole food, not its isolated components, has shown this beneficial effect on vascular health," said Emilio Ros, who led the study at the Hospital Clinic of Barcelona.
Lessening after-meal surges in blood sugar helps protect against cardiovascular disease and diabetes, most likely by lessening the increase in cholesterol-damaging free radicals that accompanies large elevations in blood sugar. This is one reason why low- glycemic index diets result in lower risk of diabetes and heart disease.
Almonds appear to not only decrease after-meal rises in blood sugar, but also provide antioxidants to mop up the smaller amounts of free radicals that still result. (Jenkins DJ, Kendall CW, Journal of Nutrition)
Researchers fed 15 healthy subjects 5 meals providing a comparable amount of carbohydrate, fat and protein: 3 test meals (almonds and bread, parboiled rice, and instant mashed potatoes) and 2 bread control meals. Blood samples, taken before each meal and 4 hours afterwards, showed levels of protective antioxidants increased after the almond meal, but decreased after the other meals.
And not only did the almond meal increase antioxidant levels, but unlike the other foods, almonds also lowered the rise in blood sugar and insulin seen after eating.
Practical Tip: So, don't just enjoy almonds as a between-meal snack. Spread a little almond butter on your toast or down the center of a stalk of celery. Add a handful of lightly roasted almonds to your salad or chop and use as a topping for pasta, steamed or healthy sautéed vegetables.
Other nuts appear to be cardio-protective as well. Research published in the British Journal of Nutrition (Blomhoff R, Carlsen MH), which identified several nuts among plant foods with the highest total antioxidant content, suggests nut's high antioxidant content may be key.
Walnuts, pecans and chestnuts have the highest antioxidant content of the tree nuts, with walnuts delivering more than 20 mmol antioxidants per 3 ounces (100 grams). Peanuts (although technically, a legume) also contribute significantly to our dietary intake of antioxidants.
Nuts' high antioxidant content helps explain results seen in the Iowa Women's Health Study in which risk of death from cardiovascular and coronary heart diseases showed strong and consistent reductions with increasing nut/peanut butter consumption. Total death rates decreased 11% and 19% for nut/peanut butter intake once per week and 1-4 times per week, respectively.
Even more impressive were the results of a review study of the evidence linking nuts and lower risk of coronary heart disease, also published in the British Journal of Nutrition. (Kelly JH, Sabate J.) In this study, researchers looked at four large prospective epidemiological studies—the Adventist Health Study, Iowa Women's Study, Nurses' Health Study and the Physician's Health Study. When evidence from all four studies was combined, subjects consuming nuts at least 4 times a week showed a 37% reduced risk of coronary heart disease compared to those who never or seldom ate nuts. Each additional serving of nuts per week was associated with an average 8.3% reduced risk of coronary heart disease.
Practical Tip: To lower your risk of cardiovascular and coronary heart disease, enjoy a handful of nuts or tablespoon of nut butter at least 4 times a week.
Greek researchers looked at the effect on systolic and diastolic blood pressure of a three-month trial during which 59 middle-aged men used either flaxseed or safflower oil in their daily diet.
Flaxseed oil is rich in the omega-3 fat, alpha-linolenic acid (ALA), which the body can metabolize into the cardioprotective long-chain omega-3 fatty acids, DHA and EPA, while safflower oil is a concentrated source of the omega-6 fat, linoleic acid (LA). The men received flaxseed oil supplying 8 grams of ALA daily or safflower oil providing 11 grams of LA per day.
At the conclusion of the 12-week study, both systolic and diastolic blood pressure was significantly lower in the men using the omega-3-rich flaxseed oil.
One possible explanation for this result is the anti-inflammatory effects of omega-3 fats. Both omega-6 and omega-3 fats are essential fatty acids: we need both types of fats to be healthy and must derive them from our food. Omega-6 fats, however, tend to promote excessive inflammation when not balanced by sufficient amounts of omega-3 fats in the diet.
Most nutrition experts believe that a health-promoting ratio of omega-6 to omega-3 fats is no higher than 4:1, and many believe the optimal ratio is 2:1. The typical American diet, however, delivers almost 10 times as much omega-6 as omega-3 fatty acids. Practical Tip: Numerous studies have shown heart-protective benefits from decreasing the ratio of omega-6 to omega-3 fats in the diet. To improve your omega 6:omega to omega-3 ratio increase your consumption of foods rich in omega-3s, such as flaxseed oil, canola oil, walnuts, and cold-water fish like wild salmon. And decrease your consumption of foods rich in omega-6 fats, such as safflower oil, corn oil, peanut oil, butter and the fats found in meats.
Increase your antioxidant intake by increasing consumption of phytonutrient-rich whole fruits, vegetables, legumes, and whole grains:
Increase your consumption of protective polyphenols by enjoying a glass of dealcoholized red wine. If you've read about the cardioprotective benefits of drinking red wine, but would prefer to avoid the alcohol, a study published in the January 2004 issue of the American Journal of Clinical Nutrition offers an alcohol-free alternative. In this six month study, female rats with an inbred susceptibility to develop cardiovascular disease were given a normal diet along with red, white or dealcoholized red wine to compare their effects on atherosclerosis development. Dealcoholized red wine provided effective protection comparable to that of either white or red wine, significantly decreasing the development of atherosclerosis. Researchers credit the polyphenolic compounds found in the wine, rather than alcohol, with these beneficial effects.
Earlier studies have suggested that the polyphenols in red wine strongly inhibit the synthesis of endothelin-1, a potent vasoconstrictor produced by the cells that make up the inner lining of the vascular system that plays a central role in the development of atherosclerosis.
Enjoy cranberries, which improve blood vessel function, thus protecting individuals with atherosclerosis against heart attack.
Polyphenols in cranberries also have very positive effects on blood vessel function. A daily dose of cranberry powder actually restores blood vessel health in pigs with atherosclerosis, shows research presented at the annual congress of the International Union of Physiological Sciences held in San Diego, CA March 31-April 5, 2005.
Earlier small studies have already demonstrated that people who drink cranberry juice have higher levels of HDL (good) cholesterol. The new study examined blood vessel health in pigs specially bred to develop high cholesterol, followed by atherosclerosis, by eight months of age.
Study results suggest that cranberries not only reduce the risk of developing heart disease by improving HDL cholesterol levels, but also improve blood vessel function, so can help individuals who already have atherosclerosis.
"Since the abnormal functioning of blood vessels is an important component of heart disease, finding ways to improve vascular function in patients with high cholesterol and atherosclerosis is critical to helping protect these patients from consequences such as heart attack or stroke," said lead researcher Kris Kruse-Elliott from the University of Wisconsin-Madison School of Veterinary Medicine.
The specially bred pigs, whose blood vessels do not function normally, were given a daily supplement of 150g cranberry juice powder per kg of their body weight. After just six months, their blood vessels acted more like those of normal pigs, said Kruse-Elliott. A control group of the specially bred pigs, which did not get cranberry juice powder, had "significantly less vascular relaxation" than either normal or cranberry-fed high cholesterol pigs.
Kruse-Elliott said the next steps are "to determine what specific components of cranberries are most important to the improvements in vascular function that we observed, exactly how they modify blood vessel relaxation, and how they can be most easily consumed as part of the diet."
Researchers think cranberries' polyphenols are responsible for their cardiovascular benefits. While humans would need to eat four to eight servings of cranberry powder, or 10-20 servings of cranberry juice, in order to achieve the levels of polyphenols given the pigs in the study, co-author Jess Reed said: "The point to be emphasized is that total polyphenol intake is very low in western diets and a diet rich in polyphenols would in fact give a daily intake that is equivalent to the levels in our cranberry feeding experiments."
Increasing the polyphenol content of your diet is easy—just make the World's Healthiest Foods the foundation of your meals! In addition to making the most of fresh cranberries around Thanksgiving when they're in season (see our recipe suggestions below), enjoy a glass of cranberry juice with breakfast or try a cranberry spritzer for a refreshing pick-me-up any time of day.
Kiwifruit, another excellent source of polyphenols, can significantly lower your risk for blood clots and reduce the amount of fats (triglycerides) in your blood, making kiwi a delicious blood-thinning alternative to aspirin for protecting cardiovascular health.
Aspirin (and other NSAIDs or non-steroidal anti-inflammatory drugs, such as Tylenol and Ibuprofen) can cause inflammation, ulcers and bleeding in the intestinal tract so severe that each year around 100,000 people are hospitalized and between 10,000 and 20,000 die from NSAID-related complications.
Unlike NSAIDs, the effects of regular kiwi consumption are all beneficial. Kiwifruit is an excellent source of vitamin C, and polyphenols, and a good source of vitamin E, magnesium, potassium, and copper, all of which may function individually or in concert to protect the blood vessels and heart.
In this study, human volunteers who ate 2 to 3 kiwifruit per day for 28 days reduced their platelet aggregation response (potential for blood clot formation) by 18% compared to controls eating no kiwi. In addition, kiwi eaters' triglycerides (blood fats) dropped by 15% compared to controls.
Increase soluble fiber intake by increasing consumption of whole grains, fruits and vegetables.
Increase omega-3 fat intake by increasing consumption of cold water fish, flaxseed and walnuts.
Increase intake of oleic acid (the monounsaturated fat found in olive oil that has been shown to lower LDL cholesterol) by increasing consumption of hazelnuts, California avocado, almonds, pecans, pistahios, cashews and Brazil nuts.
Enjoy tomato juice as a snack or to start your lunch or dinner. Tomato juice is an effective blood thinner, suggests Australian research published in the August 2004 issue of the prestigious Journal of the American Medical Association. In this study, 20 people with type 2 diabetes were given 250 ml (about 8 ounces) of tomato juice or a tomato-flavored placebo daily. Subjects had no history of clotting problems and were taking no medications that would affect blood clotting ability. After just 3 weeks, platelet aggregation (the clumping together of blood cells) was significantly reduced among those drinking real tomato juice, while no such effect was noted in those receiving placebo.
While of special benefit for those with type 2 diabetes who are at increased risk of cardiovascular disease, the blood thinning effects of tomato juice are noteworthy for anyone at higher risk of blood clot formation.
Drinking tea may help lower the amount of LDL (bad) cholesterol in the blood, a small study conducted at the Agricultural Research Service Beltsville Human Nutrition Research Center suggests. Seven men and eight women, aged 20 to 70, participated in this nutrition research, which investigated the effects of three beverages—black tea, a placebo of tea-flavored water, and tea-flavored water with a similar amount of caffeine added to that found in black tea. During the 12 week randomized crossover study, participants ate a diet moderately low in fat and drank five servings of tea, tea-flavored water or caffeinated tea-flavored water daily for a three week period, after which they rotated through the other two choices.
While drinking tea, participants' total cholesterol was reduced an average of 6.5%, LDL cholesterol 11.1%, apoliopoprotein B 5% and lipoprotein(a) 16.4%. (apo B is a protein molecule, one of which is found on the surface of each molecule of LDL. Lp(a) is another protein that bonds to the LDL molecule, rendering it much more likely to stick to the blood vessel lining and initiate the atherogenic process. High levels of either indicate increased risk of cardiovascular disease).
Limit your consumption of animal products derived from domesticated animals such as milk, cheese, and red meats.
Avoid processed foods such as snack foods, white bread and baked goods made from refined flours.
Avoid consumption of fried foods, margarine, overheated vegetable oils, and processed foods containing trans fats.
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