The World's Healthiest Foods

Whole grains lower risk of cardiovascular disease and type 2 diabetes

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 cardiovascular disease, but metabolic syndrome and type 2 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:

  • Abdominal obesity (excessive fat in and around the midsection)
  • Atherogenic dyslipidemia (high levels of blood fats that promote plaque buildup in artery walls- high triglycerides and LDL cholesterol- and low levels of protective HDL cholesterol)
  • High blood pressure
  • Insulin resistance or glucose intolerance (inability of the cells to respond to insulin and absorb blood sugar)
  • Increased susceptibility to blood clot formation (increased blood levels of fibrinogen or plasminogen activator inhibitor-1-compounds involved in blood clot formation)
  • Proinflammatory state (increased blood levels of pro-inflammatory C-reactive protein, another risk factor for cardiovascular disease)

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.

Beta-glucan in Barley Lowers LDL, Increases HDL Fractions

Adding barley to your healthy way of eating may help you significantly lower your total and LDL cholesterol, suggests a study published in the November 2004 issue of the American Journal of Clinical Nutrition.

In this study of 25 individuals with high cholesterol (9 postmenopausal women, 9 premenopausal women, and 7 men), adding barley to the American Heart Association Step 1 diet resulted in a significant lowering in total cholesterol in all subjects, plus their amount of large LDL and large and intermediate HDL fractions (which are considered less atherogenic) increased, and the smaller LDL and VLDL cholesterol (the most dangerous fractions) greatly decreased. One reason for these very beneficial effects¡ªa compound found in barley's fiber called beta-glucan. Beta glucan lowers cholesterol by binding to bile acids (which the body uses to digest fats and makes in the liver from cholesterol) and ferries it out of the body in the feces. So, the body must make new bile acids, and to do so, the liver must use up more cholesterol, thus lowering the amount in circulation.

Unique Antioxidant in Oats Protects LDL Cholesterol

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¡ªthe 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.

Whole Brown Rice Lowers LDL Cholesterol

Here's yet another reason to rely on whole foods, such as brown rice, for your healthy way of eating: the oil in whole brown rice, not its fiber, lowers cholesterol.

When Marlene Most and colleagues from Louisiana State University evaluated the effects of rice bran and rice bran oil on cholesterol levels in volunteers with moderately elevated cholesterol levels, they found that rice bran oil, but not rice bran, lowered their LDL (bad) cholesterol.

The study, published in the January 2005 issue of the American Journal of Clinical Nutrition, was divided into two parts. First, 26 subjects ate a diet including 13-22g of dietary fiber each day for three weeks, after which 13 switched to a diet that added defatted rice bran to double their fiber intake for five weeks. In the second part of the study, a randomized crossover trial, 14 subjects ate a diet with rice bran oil for 10 weeks.

While the diet including only defatted rice bran did not lower cholesterol, the one containing rice bran oil lowered LDL cholesterol by 7%. Since all the diets contained similar fatty acids, the researchers concluded that the reduction in cholesterol seen in those receiving rice bran oil must have been due to other constituents such as the unsaponifiable compounds found in rice bran oil. The scientists suggest that the unsaponifiables present in rice bran oil could become important functional foods for cardiovascular health. But why extract just one beneficial compound from brown rice when you can reap all the cardioprotective benefits supplied by the matrix of nutrients naturally present in this delicious whole food? In addition to unsaponifiables, this whole grain also supplies hefty doses of heart-healthy fiber, magnesium, and B vitamins.

Almonds Improve Cholesterol Profile

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.

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