Hypertension, or high blood pressure, is a common disease in both men and women. It’s estimated that 2 million new cases are diagnosed each year in the United States. Hypertension is called the "silent killer" because it generally produces no overt symptoms even while causing widespread damage to the heart, brain, kidneys, and other vital organs. Although hypertension can strike anyone at any time of their life, it’s most commonly seen in older individuals. In fact, over 70% of American women and 50% of men over age 70 have hypertension. In addition to advanced age, other risk factors for hypertension include high cholesterol levels, smoking, obesity, and diabetes.1

How High Is Too High?

When doctors place a blood pressure cuff on your arm, they are measuring [as millimeters of mercury (mm Hg)] the force exerted by your blood against the walls of your arteries. Actually two distinct pressures go into blood pressure measurement:

  • Systolic pressure is the maximum force exerted during the contraction of the left ventricle of the heart. It is typically the higher of the two numbers that are used to describe "blood pressure."
  • Diastolic pressure is the minimum force exerted as the heart relaxes between beats. It is the lower of the two numbers.
  • Although these definitions are constantly undergoing revision, normal blood pressure is usually defined as a systolic pressure of 130 mm Hg or less and a diastolic pressure of 85 mm Hg or less. Hypertension is defined as a pressure of 140/90 mm Hg or higher.
  • An elevation in just one of the two pressures (systolic or diastolic) can have disastrous long-term health consequences. Isolated systolic hypertension is the most common form of high blood pressure seen in older adults and is thought to be a significant predictor of heart attacks and strokes. Isolated diastolic hypertension is also a strong risk factor for heart attacks and strokes, especially in younger adults.

The Business of Hypertension

Many of the most heavily prescribed medications in the United States are antihypertensives. With drug costs rising at least 12% per year since 1993, patients, especially the elderly, can end up spending thousands of dollars a year on prescription drugs to control their blood pressure. Although the majority of these drugs (including diuretics, calcium channel blockers, ACE* inhibitors, and ARBs ) work well, they can all have side effects ranging from troublesome to potentially deadly, including hyperglycemia (high blood glucose), tinnitus (constant ringing or buzzing in the ears), kidney damage, heart failure, and sexual dysfunction. Much to the embarrassment of the pharmaceutical industry, recent research has shown that the simplest, oldest, and least expensive of these drugs, the diuretics, are typically as effective and as safe as the newer, more sophisticated, and more expensive agents.

Controlling Hypertension Naturally

For those who hesitate to use antihypertensive drugs, nondrug strategies may significantly help in controlling high blood pressure. The Dietary Approaches to Stop Hypertension (DASH) diet is now recommended as a first-line approach in managing the disease. The DASH diet is high in fruits, vegetables, and other nutritious foods that are rich in potassium, calcium, and magnesium. People following the DASH diet are encouraged to decrease their saturated fats and replace them with foods that are high in monounsaturated fats and omega-3 fatty acids.

Other natural ways to control hypertension include not smoking (excellent advice for everyone!), lose excess weight, and restrict salt intake – the current recommendation is for people with hypertension to limit their salt intake to 2400 mg (about 1 teaspoon) per day.

Arginine — The Source of Nitric Oxide

Another natural way to help improve blood pressure is with nutritional supplements. Key among these is arginine, an amino acid that is vitally important for overall good health. Besides playing a positive role in blood pressure control, arginine (technically, L-arginine, but the L can be taken for granted) can also be helpful in a variety of other conditions, including type 2 diabetes and sexual dysfunction in both women and men.

How does arginine work its wonders? The answer lies in its ability to produce nitric oxide (NO), a simple gas that performs some amazing feats in the human body.

Nitric oxide penetrates and crosses the membranes of almost all cells in the body, where it helps regulate many cellular functions. In blood vessels, NO is vitally important because it regulates the tone of the smooth muscle cells that surround arteries. If these cells become dysfunctional, they can cause spasms or constrictions of the blood vessels, which can then lead to hypertension.

Arginine Reduces Blood Pressure in Healthy Adults

More and more studies are confirming the benefits of arginine supplementation for blood pressure. One recent study in Italy examined blood pressure changes among six healthy male volunteers who were placed on three different diets:2 1) The first consisted of foods that contained 3 to 4 grams of arginine per day. 2) The second diet was high in arginine-rich foods (nuts and legumes), so that these volunteers consumed about 10 grams of arginine daily. 3) The third diet was the same as the first, except for the addition of 10 grams of supplemental arginine daily.



Figure 1. Forearm blood flow increases in response to the drug isoproterenol. When intra-arterial arginine was give concomitantly, blood flow increased significantly in men with essential hypertension and in normotensive men with a positive family history of hypertension. * P <0.05. Adapted from Schlaich et al, 2004.

After only 1 week, the men on diets 2 and 3 registered significant decreases in blood pressure compared to those on diet 1. Interestingly, a statistically significant reduction in blood glucose (blood sugar) was also seen in the men on diets 2 and 3. Despite some serious limitations of this study (eg, short duration and a small number of subjects), the authors concluded that "an approximately two-fold increase in dietary L-arginine intake had significant hemodynamic and metabolic effects in a group of healthy men."

The antihypertensive effects of arginine in young men were recently demonstrated in another study conducted in Australia.3 The subjects included 12 young men with early essential hypertension, as well as 28 normotensive young men, 14 with a positive family history of hypertension and 14 with a negative history. The investigators measured forearm blood flow following the infusion of the vasodilating drug isoproterenol before and after the subsequent infusion of arginine. The vasodilator effect of isoproterenol, a ß-adrenergic agonist, is at least partly mediated via the action of arginine and NO. As shown in Figure 1, concomitant infusion of isoproterenol and L-arginine resulted in significantly improved blood flow in hypertensive men and in normotensive men who were genetically predisposed to hypertension, but not in normotensive men with no family history of high blood pressure.

How Much Arginine is Enough?

The recommended serving sizes for maximum benefit are 18 g/day of arginine for men and 12 g/day for women, preferably taken all at once on an empty stomach, about an hour before exercise or athletics or sexual activity, or at bedtime. This optimizes the release of growth hormone by the pituitary gland, which is stimulated by arginine, and provides NO-mediated vasodilation when it is most needed.

For supporting proper cardiovascular function, it’s preferable to take half the maximum amount of arginine and divide the daily serving into three portions of 3 g (for men) or 2 g (for women) each. The totals are then 9 g/day for men and 6 g/day for women. It’s best to drink the three portions at midmorning, midafternoon, and bedtime so as to avoid conflict with protein-containing meals, which could interfere with the absorption of arginine.


* ACE = angiotensin converting enzyme
ARBs = angiotensin receptor blockers

FREE Subscription

  • You're just getting started! We have published thousands of scientific health articles. Stay updated and maintain your health.

    It's free to your e-mail inbox and you can unsubscribe at any time.
    Loading Indicator