Hypertension is a consistent elevation in blood pressure. "Blood pressure" signifies the resistance produced each time the heart beats and sends blood coursing through the arteries. Between beats, the heart relaxes, and blood pressure drops. The lowest pressure is referred to as the diastolic pressure. The peak pressure exerted by this contraction is the systolic pressure. A normal blood pressure reading for an adult is: 120 (systolic) / 80 (diastolic).

Hypertension is a major risk factor for a heart attack and is generally regarded as the greatest risk factor for a stroke. Hypertension (high blood pressure) is aptly called "a silent killer," because people are often unaware of having hypertension until a stroke or heart event brings the message home.

The physiological changes related to hypertension can frequently be related to lifestyle patterns that are easily modifiable. For example, being overweight may contribute to hypertension, because it increases the work required by the heart. Making healthy eating choices can be an important, easy and enjoyable step towards maintaining healthy blood pressure levels.

Eat more

• Cold water fish such as salmon, tuna, herring, mackerel and halibut for their beneficial omega 3 fatty acid
• Onions and garlic
• Olive oil
• Celery
• Organically grown fruits and vegetables, especially beets, leafy greens and cruciferous vegetables such as broccoli, cauliflower and cabbage
• Whole grains
• Legumes
• Potatoes

Avoid saturated fat, sugar, caffeine, alcohol, excess sodium

What is Hypertension

Elevated blood pressure is a major risk factor for a heart attack and is generally regarded as the greatest risk factor for a stroke. ¡°Blood pressure¡± signifies the resistance produced each time the heart beats and sends blood coursing through the arteries.

The peak pressure exerted by this contraction is the systolic pressure. Between beats, the heart relaxes, and blood pressure drops. The lowest pressure is referred to as the diastolic pressure. A normal blood pressure reading for an adult is: 120 (systolic) / 80 (diastolic).

High blood pressure is divided into different levels:

• Borderline (120¨C160/90¨C94)
• Mild (140¨C160/95¨C104)
• Moderate 140¨C180/105¨C114)
• Severe (160+/115+)

Physicians are primarily concerned with diastolic pressure (the second number in the blood pressure reading), but systolic pressure is also important. Individuals with a normal diastolic pressure (under 82 mm Hg) but elevated systolic pressure (over 158 mm Hg) have double the risk of death due to heart attack or stroke compared to individuals with normal systolic pressures (under 130 mm Hg).

Blood pressure typically goes up as a result of stress or physical activity, but in a person with high blood pressure, is elevated even at rest.

Over sixty million Americans have high blood pressure, including more than half of all Americans aged 65-74 years, and almost three-fourths of all African-Americans in the same age group.

Most patients with high blood pressure are in the borderline-to-moderate range, a group in which almost all cases of high blood pressure can be brought under control through changes in diet and lifestyle. In fact, in cases of borderline-to-mild hypertension, healthful changes in diet and lifestyle (discussed below) have proven superior to drugs in head-to-head comparisons.

In addition, in some people, the drugs typically prescribed to lower blood pressure produce the very thing they are trying to prevent: a heart attack. Several well-designed long-term clinical studies have found that people who take blood-pressure-lowering drugs (typically diuretics and/or beta-blockers) actually suffer from unnecessary side effects (e.g., fatigue, headaches, and impotence), including an increased risk of heart disease.

Frequent Signs and Symptoms

• Usually none--blood vessels do not have nerves, so no symptoms are felt until the condition becomes severe
• Typically discovered as part of a routine check up

A hypertensive crisis may be indicated by:

• Headache, drowsiness, confusion
• Numbness and tingling in hands and feet
• Coughing blood; nosebleeds
• Severe shortness of breath
• Vague but intense feeling of discomfort

Related Tests

• Blood pressure screening (In addition to physicians' offices, blood pressure may sometimes be checked at pharmacies, fire stations, and public health offices. There are also simplified home systems.)
• Blood lipids, blood triglycerides, blood insulin or oral insulin tolerance (Syndrome X testing)
• Methionine loading test (for high homocysteine levels)

Sodium and potassium

Excessive consumption of dietary sodium (from table salt), coupled with diminished dietary potassium, is a common cause of high blood pressure, especially in ¡°salt-sensitive¡± individuals. Numerous studies have shown that sodium restriction alone does not improve blood pressure control in most people, but must also be accompanied by a high potassium intake.

In our society, only 5 percent of sodium intake comes from the natural ingredients in food. Prepared foods contribute 45 percent of our sodium intake, 45 percent is added in cooking, and another 5 percent is added as a condiment. All the body requires in most instances is the salt that is naturally present in food.

Most Americans have a sodium-to-potassium ratio greater than 2:1, meaning that most people ingest twice as much sodium as they do potassium. Researchers recommend a dietary sodium-to-potassium ratio of less than 1:5 to maintain health. This is 10 times the average intake of potassium, yet even this may not be optimal. A natural diet rich in fruits and vegetables can produce a sodium-to-potassium ratio of under 1:100, as most fruits and vegetables have a sodium-to-potassium ratio of less than 1:50.

Calcium, magnesium, and vitamin C

Epidemiological and clinical studies have found numerous links between inadequate amounts of these three nutrients and high blood pressure.

Saturated fats

A high intake of saturated fats has been conclusively linked to high cholesterol levels and atherosclerosis. These "hard" fats become incorporated within the walls of blood vessels, which then lose their elasticity.

Essential fats

Population and autopsy studies have demonstrated that people who consume a diet rich in omega-3 essential fats from either fish or vegetable sources have the lowest degree of cardiovascular disease and, conversely, those who consume the least omega-3 essential fats have the highest degree of cardiovascular disease.

Dietary fiber

Fiber in the diet is an absolute key in helping control blood levels of lipids and sugar, and a low dietary intake of fiber is associated with atherosclerosis (hardening of the arteries).

Caffeine and nicotine

Caffeine (and nicotine--another reason not to smoke) is a stimulant that promotes the body's stress response, releasing hormones that rapidly elevate blood pressure.

Alcohol

In susceptible individuals, even moderate alcohol consumption causes a steep rise in blood sugar and increases the production of free radicals, both of which damage arteries and can contribute to chronically elevated blood pressure.

Excess Sugar

While too much intake of dietary sugar-particularly in the form of added table sugar (sucrose)-has not clearly been shown to be a direct cause of high blood pressure, some clear stepping stones between excessive sugar intake and problems with blood pressure regulation have been identified in scientific studies. The two most important stepping stones in this regard are (1) insulin resistance and (2) unwanted oxidative stress and inflammatory activity.

In studies on rats and mice, excessive intake of sucrose, and in some studies fructose, has been linked to increased levels of insulin in the blood, glucose intolerance, formation of too many reactive substances in the bloodstream (including reactive oxygen species and reactive aldehydes), and unwanted inflammation in the walls of the blood vessels. This combination of events may be accompanied by problems in the autonomic nervous system and imbalances that can lead to excessive constriction of the blood vessels and hypertension. The pattern of events here is complicated, but it leaves no doubt that problems involving insulin resistance and problems involving hypertension are connected problems.

It's important to note here that sucrose and fructose are two of the many sugars found in whole, natural foods, and they are seldom present in isolated form or in overwhelmingly high amounts. (Fruit might be considered an exception to this rule, since the sweet taste of most fruits comes predominantly from fructose.) It usually takes a processed food like white, refined, granulated table sugar to expose us to levels of sucrose as excessive as the levels used in animal studies. With respect to fructose, we're also unlikely to reach levels of excess comparable to the research study levels unless we are consuming large amounts of processed fruit juice or dried fruit. Whole, natural fruits consumed in moderate amounts are very unlikely to bring us close to sugar excess, even with fructose as their primary sugar. We expect future research to uncover more and more details about the relationship between insulin resistance, chronic low-level inflammation, and intake of highly processed foods-including concentrated, sugar-based sweeteners and the pre-packaged foods that contain them.

Essential fats

Over sixty double-blind studies have demonstrated that either fish oil supplements or flaxseed oil, the two best sources of omega-3 essential fats, are very effective in lowering blood pressure. Fish oils have typically produced a more pronounced effect than flaxseed oil because the dosage of fish oils used was quite high (equal to ten capsules daily).

Flaxseed oil may be the better choice for lowering blood pressure, especially when cost-effectiveness is considered. Along with reducing the intake of saturated fat, 1 tablespoon per day of flaxseed oil should lower both the systolic and diastolic readings by up to 9 points.

Potassium

Several studies show that potassium supplementation alone can produce significant reductions in blood pressure in hypertensive subjects. Typically, these studies have utilized dosages ranging from 2.5 to 5.0 grams of potassium per day. Significant drops in both systolic and diastolic values have been achieved.

In one study, potassium supplementation lowered systolic blood pressure an average of 12 points and diastolic blood pressure an average of 16 points. Potassium supplementation may be especially useful in the treatment of high blood pressure in persons over the age of sixty-five, who often do not fully respond to blood-pressure-lowering drugs.

In one double-blind study of eighteen patients whose average age was 75, with a systolic blood pressure of greater than 160 mm Hg and/or a diastolic blood pressure of greater than 95 mm Hg, those who received potassium chloride (supplying 2.5 grams of potassium) each day for four weeks experienced a drop of 9 points in systolic and 7 points in diastolic pressure-comparable results to drug therapy without its negative side effects.

Using foods or food-based potassium supplements to meet the human body¡¯s high potassium requirements rather than pills is suggested, since potassium salts can cause nausea, vomiting, diarrhea, and ulcers when given in pill form at high dosages. These effects are not seen when potassium levels are increased through diet only.

Caution: Check with your physician before taking potassium. Individuals with kidney disease do not handle potassium in the normal way and are likely to experience heart disturbances and other consequences of potassium toxicity.

Potassium supplementation is contraindicated when using a number of prescription medications, including digitalis, potassium-sparing diuretics, and the angiotensin-converting-enzyme-inhibitor class of blood-pressure-lowering drugs. People with kidney disease or severe heart disease should not take magnesium or potassium unless under the direct advice of a physician.

Magnesium

Magnesium is second only to potassium in its concentration within cells and interacts with potassium in many body systems. Studies suggest that low levels of potassium within cells may be the result of low magnesium intake.

Population studies provide considerable evidence that a high intake of magnesium is associated with lower blood pressure. Numerous studies have demonstrated an inverse correlation between water hardness (water high in magnesium) and high blood pressure. Where magnesium content of the water was high, there were fewer cases of high blood pressure and heart disease.

Similarly, studies have found that when dietary intakes of magnesium were high, blood pressure was lower. Magnesium supplementation is particularly helpful in lowering blood pressure if:

• An individual is taking a diuretic, since diuretics cause magnesium depletion.
• High blood pressure is associated with a high level of renin, an enzyme released by the kidneys that leads to the formation of chemicals that cause blood vessels to constrict and blood pressure to increase.
• An individual has elevated intracellular sodium or decreased intracellular potassium levels (as measured by red blood cell studies).

Absorption studies indicate that magnesium is easily absorbed orally, especially in the citrate form. In addition, while inorganic magnesium salts (like magnesium oxide) often cause diarrhea at higher dosages, organic forms of magnesium (magnesium citrate or aspartate) generally do not.

Vitamin C and flavonoids

Studies have shown that the higher the intake of vitamin C the lower the blood pressure. One of the ways vitamin C helps keep blood pressure in the normal range is by promoting the excretion of lead.

Chronic exposure to lead from environmental sources, including drinking water, is associated with high blood pressure and increased cardiovascular mortality. Areas with a soft water supply have higher lead concentrations in drinking water due to the acidity of the water. Soft water is also low in calcium and magnesium¡ªtwo minerals that protect against high blood pressure.

Flavonoids (which co-occur naturally with vitamin C in many colorful fruits and vegetables) support the antioxidant actions of vitamin C and help strengthen and protect the inner lining of blood vessels.

Vitamin E

Of all the antioxidants, the fat-soluble antioxidant, vitamin E may offer the most protection against hardening of the arteries because it is easily incorporated into the LDL-cholesterol molecule where it prevents free radical damage. Vitamin E not only reduces LDL peroxidation, but it also improves plasma LDL breakdown, inhibits excessive platelet aggregation, increases HDL-cholesterol levels, and increases the breakdown of fibrin, a clot-forming protein.

Coenzyme Q10

Coenzyme Q10 or CoQ10 is an essential component of the mitochondria¡ªthe factories where energy is produced in our cells. Although CoQ10 can be synthesized within the body, deficiency has been found in 39% of patients with high blood pressure.

In several studies, CoQ10 has been shown to lower blood pressure approximately 10% in patients with hypertension; however, not until after four to twelve weeks of therapy. CoQ10 seems to lower blood pressure by lowering cholesterol levels and stabilizing the vascular system via its antioxidant properties. These actions reduce resistance to blood flow through the arteries.

Vitamin B3 (niacin) Niacin is extremely important for controlling blood lipid levels and for proper metabolism of carbohydrates and fats. Timed-release niacin may be employed to avoid flushing. Liver toxicity may occur with high doses of niacin.

Folic acid, vitamins B6 and B12, and choline

These B-complex-related vitamins make significant contributions to the normal function of the innermost layer of the blood vessels, which is necessary for maintaining normal blood pressure. They are also necessary for our bodies to be able to metabolize homocysteine into other, useful compounds. An intermediate product of normal cellular metabolism, homocysteine accumulates-if not converted into methionine or cysteine via the action of folic acid and vitamins B12 and B6-and can damage the blood vessels, keeping them in a constant state of injury.

Folic acid is so important for cardiovascular function that a major study concluded that 400 micrograms per day of folic acid could prevent 28,000 cardiovascular deaths per year in the United States. The average daily intake of folic acid is 280 to 300 micrograms, about half of which is absorbed.(Forman JP, Rimm EB, et al. JAMA)

Substances and conditions that can negatively affect folic acid, vitamin B12, and vitamin B6 status include methotrexate, phenytoin, theophylline, dopamine, Isoniazid, tartrazine (yellow dye #5), insufficient stomach acid, intestinal flora imbalances, diarrhea, and smoking.

L-arginine

L-arginine is a common amino acid from food, but its importance increases in those with hypertension. In the body (specifically within those hard-working blood vessels) it is converted into nitric oxide, a chemical that helps keep the inner walls of blood vessels smooth and normally allows blood vessels to relax (among many other extremely important functions).

Individuals with hypertension have a harder time maintaining normal nitric oxide levels, which may also relate to other significant health issues such as diabetes and heart problems. The kidneys are particularly sensitive to the levels of l-arginine, nitric oxide, and related chemicals. Stressful experiences and aging may also result in lower l-arginine levels.

Dietary intake levels of l-arginine vary considerably, but they range from 1 to over 4 grams per day. The consumption of nuts, which contain relatively high levels of arginine, has a very strong negative correlation to the risk of coronary events.

Soy flour, wheat bran, hazelnuts, and walnuts all contain high levels of both arginine and folic acid. Fish contains high levels of arginine and essential fats. A major source of dietary arginine in the Western diet is meat; however, meat also contains high levels of saturated fats as well as methionine, the precursor to homocysteine.

Soy flour, wheat bran, and most nuts contain relatively low levels of methionine. It is advisable to limit arginine intake in those with active or latent herpes simplex or herpes zoster infections.

Excessive intakes of particular nutrients are clearly related to the development of hypertension; generally, the greater the quantity in which these nutrients appear in foods, the more these foods are processed. The most significant excesses include:

• Calories contribute to excess weight and a greater burden of disposing of unnecessary nutrients into circulating blood lipids and body fat.
• Saturated fats, which may be deposited into circulating blood lipids and in the delicate inner layers of blood vessels, decreasing their elasticity, integrity, and healing capacity.
• Sodium¡ªbecause it is added to foods, it frequently occurs in a much higher proportion than minerals (especially potassium and magnesium) that help balance the actions of sodium in the body.

Another increasingly important possibility is the ingestion of heavy metals and other toxins that affect the function of the blood vessels. Significant among these are lead, mercury, and cadmium.

Lead can occur in high levels in tap water, in old, peeling paint, and after sanding wood floors. Mercury can occur in high levels in some types of fish and is also present in amalgam tooth fillings.

Cadmium can occur in high levels in air near highways and is also present in some batteries. These heavy metals are difficult for the body to excrete, and can remain in the body and affect function for years.

General Guidelines:

• Increase your consumption of plant foods: vegetarians generally have lower blood pressure and a lower incidence of high blood pressure and other cardiovascular diseases than non-vegetarians. Vegetarians and non-vegetarians consume similar amounts of sodium, but vegetarians consume more potassium, complex carbohydrates, essential fatty acids, fiber, calcium, magnesium, and vitamin C, and less saturated fat and refined carbohydrates, all of which have been shown to have a favorable influence on blood pressure.
• Increase your consumption of green leafy vegetables, which are fat-free, rich sources of calcium and magnesium, both of which have beneficial effects on blood pressure.
• Increase your consumption of whole grains and legumes: A high fiber diet can help lower cholesterol levels.
• Increase your consumption of broccoli and citrus fruits, which are rich in vitamin C. Population-based and clinical studies show that the higher the intake of vitamin C, the lower the blood pressure.
• Consume 4 ribs of celery daily. A compound found in celery, 3-n-butyl phthalide, has been shown to lower blood pressure experimentally. In animals, a very small amount of 3-n-butyl phthalide lowered blood pressure by 12-14 percent, and also lowered cholesterol levels by about 7 percent. Four ribs of celery supply the equivalent dose in humans. If you are worried about your celery naturally containing too much sodium, it's unlikely that you need to. The amount of natural sodium found in 4 stalks of celery is about 200-400 milligrams depending on the size of the stalk, and that's likely to be an amount you can fit fairly easily into a meal plan well-suited to blood pressure regulation.
• Consume both garlic and onions liberally: The sulfur-containing compounds in garlic and onions have been shown to lower blood pressure in cases of hypertension. Garlic supplements may also be of benefit.
• Avoid saturated fats (found mainly in animal products), margarine and foods containing trans-fatty acids (found in processed foods)¡ªa great deal of research links these fats to heart disease, strokes, and cancer.
• Rely on eggs, low-fat dairy products, fish and poultry as your primary sources of animal protein. Limit consumption of red and processed meats to no more than 2 servings per week.
• Avoid processed foods: their primary ingredients (sugars, refined carbohydrates, and trans-fats) elevate cholesterol levels, blood pressure, and the risks for obesity and diabetes.
• Increase your consumption of omega-3 essential fats by consuming flaxseed oil (1 tablespoon per day) and/or eating cold-water fish¡ªsalmon, mackerel, tuna, herring, halibut (4 ounces at least 3 times weekly). These fats "thin" the blood and can have numerous beneficial effects on cardiovascular health.

• Bellamy MF, McDowell IF, Ramsey MW, et al. Hyperhomocysteinemia after an oral methionine load acutely impairs endothelial function in healthy adults. Circulation. 1998;98:1848-1852. 1998.
• Bland JS, Levin B, Liska D, et al. Clinical Nutrition: A Functional Approach. 1999 Institute for Functional Medicine, Gig Harbor, WA p.175 1999.
• Boushey CJ, Beresford SA, Omenn GS, Motulsky AG. A quantitative assessment of plasma homocysteine as a risk factor for vascular disease. JAMA. 1995;274(13):1049-1057. 1995.
• Brockes C, Buchli C, Locher R et al. Vitamin E prevents extensive lipid peroxidation in patients with hypertension. Br J Biomed Sci 2003; 60(1):5-8 2003.
• Clarkson P, Adams MR, Powe AJ, et al. Oral L-arginine improves endothelium-dependent dilation in hypercholesterolemic young adults. J Clin Invest. 1996;97(8):1989-1994. 1996.
• de Lorgeril M. Dietary arginine and the prevention of cardiovascular diseases. Cardiovasc Res. 1998;37:560-563. 1998.
• Forman JP, Rimm EB, Stampfer MJ, Curhan GC. Folate intake and the risk of incident hypertension among US women. JAMA. 2005 Jan 19;293(3):320-9 2005. PMID:15657325.
• Fraser GE. Diet and coronary heart disease: beyond dietary fats and low-density-lipoprotein cholesterol. Am J Clin Nutr. 1994;59(Suppl):1117S-1123S 1994.
• Kramer HJ, Gonick HC, Lu E. In vitro inhibition of Na-K-ATPase by trace metals: relation to renal and cardiovascular damage. Nephron. 1986;44(4):329-336. 1986.
• Lerman A, Burnett JC, Higano ST, McKinley LJ, Holmes DR. Long-term L-arginine supplementation improves small-vessel coronary endothelial function in humans. Circulation. 1998;97(21):2123-2128. 1998.
• Luscher TF, Richard V, Tschudi M, Yang Z, Boulanger C. Endothelial control of vascular tone in large and small coronary arteries. J Am Coll Cardiol. 1990;15:519-527. 1990.
• Milakofsky L, Harris N, Vogel WH. Effects of repeated stress on plasma arginine levels in young and old rats. Physiology & Behavior. 1993;54:725-728. 1993.
• Nash D, Magder L, Lustberg M et al. Blood lead, blood pressure, and hypertension in perimenopausal and postmenopausal women. JAMA. 2003 Mar 26; 289(12):1523-32. 2003.
• National Research Council. Recommended Dietary Allowances, 10th ed. Washington, DC: National Academy Press; 1989. 1989.
• Nava E, Luscher TF. Endothelium-derived vasoactive factors in hypertension: nitric oxide and endothelin. J Hypertens. 1995;13(Suppl 2):S39-S48. 1995.
• Parr A, Mellon F, Colquhoun I, Davies H. Dihydrocaffeoyl Polyamines (Kukoamine and Allies) in Potato (Solanum tuberosum) Tubers Detected during Metabolite Profiling. J Agric. Food Chem, 53 (13), 5461 -5466, 2005. 2005.
• Reaven G. Pathophysiology of insulin resistance in human disease. Physiol Rev. 1995;75(3):473-486. 1995.
• Ruano J, Lopez-Miranda J, Fuentes F, Moreno JA, Bellido C, Perez-Martinez P, Lozano A, Gomez P, Jimenez Y, Perez Jimenez F. Phenolic content of virgin olive oil improves ischemic reactive hyperemia in hypercholesterolemic patients. J Am Coll Cardiol. 2005 Nov 15;46(10):1864-8. 2005. PMID:16286173.
• Selhub J, Jacques PF, Wilson PW, Rush D, Rosenberg IH. Vitamin status and intake as primary determinants of homocysteinemia in an elderly population. JAMA. 1993;270(22):2693-2698. 1993.
• Shimakawa T, Nieto J, Malinow, R, Chambless LE, Schreiner PJ, Szklo M. Vitamin intake: a possible determinant of plasma homocyst(e)ine among middle-aged adults. Ann Epidemiol. 1997;7(4):285-293. 1997.
• Steffen LM, Kroenke CH, Yu X, Pereira MA, Slattery ML, Van Horn L, Gross MD, Jacobs DR Jr. Associations of plant food, dairy product, and meat intakes with 15-y incidence of elevated blood pressure in young black and white adults: the Coronary Artery Risk Development in Young Adults (CARDIA. Am J Clin Nutr. 2005 Dec;82(6):1169-77. 2005. PMID:16332648.
• Tawakol A, Migrino RQ, Aziz KS, Waitkowska J, Holmvang G, Alpert NM, Muller JE, Fischman AJ, Gewirtz H. High-dose folic Acid acutely improves coronary vasodilator function in patients with coronary artery disease. J Am Coll Cardiol. 2005 May 17;45(10):1580-4. Epub 2005 Apr 26. 2005. PMID:15893170.
• Toledo E, Delgado-Rodriguez M, Estruch R et al,. Low-fat dairy products and blood pressure: follow-up of 2290 older persons at high cardiovascular risk participating in the PREDIMED study. The British Journal of Nutrition. Cambridge: Jan 2009. Vol. 101, Iss. 1; pg. 59-67. 2009.
• Webb AJ, Patel N, Loukogeorgakis S, et al. Acute blood pressure lowering, vasoprotective, and antiplatelet properties of dietary nitrate via bioconversion to nitrite. Hypertension. 2008 Mar;51(3):784-90. 2008. PMID:18250365.
• Welch GN, Loscalzo J. Homocysteine and atherothrombosis. N Engl J Med. 1998;338(15):1042-1050. 1998.
• Wennmalm A. Endothelial nitric oxide and cardiovascular disease. J Int Med. 1994;235:317-327. 1994.