Arginine for Top-to-Bottom Benefits

estern medicine has made huge advances in just a hundred years. Diseases such as smallpox, polio, and tuberculosis have been eradicated or reduced to just a few isolated incidents. These days, the major health concerns of people in our society are chronic diseases, especially the potentially fatal ones, such as heart disease and cancer. While these diseases do kill a great many people, there is a "silent killer" that afflicts over 50 million people in the United States and contributes to the death of almost a quarter-million of them a year.¹

The Silent Killer

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 it causes widespread damage to the victim's heart, brain, kidneys, and other vital organs. Although it 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 American men over the age of 70 have hypertension. Other risk factors for this disease include high cholesterol levels, smoking, obesity, and diabetes.¹

How High Is Too High?

What doctors measure when they place a blood pressure cuff on your arm is the force exerted by your blood against the walls of your arteries, in units of millimeters of mercury (mm Hg).* There are actually two distinct pressures measured - systolic pressure (the maximum force exerted as the heart contracts) and diastolic pressure (the minimum force exerted as the heart relaxes between beats). Normal blood pressure is defined as a systolic pressure of 130 mm Hg or below and a diastolic pressure of 85 mm Hg or below. High normal is pressures of 131-139 systolic and 86-89 diastolic. Hypertension is defined as a pressure of 140 systolic over 90 diastolic and above.

*The chemical symbol for mercury is Hg because it's derived from the Latin word for mercury, hydrargyrum.

Blood pressure generally rises and falls throughout the day in a cyclic rhythm and is influenced by many factors, such as exercise and emotional stress (including that of being in a doctor's office). To get a good idea of what your blood pressure really is, it's necessary to make numerous measurements at different times and average them.

What Causes High Blood Pressure?

Most cases of high blood pressure have no obvious medical cause and are referred to as essential, or primary, hypertension. Although doctors still don't know what causes this most common type of hypertension, current research indicates that a complex interaction between genetic, environmental, and other variables is a significant factor. Secondary hypertension, which is much less common, is high blood pressure caused by known medical conditions, such as kidney disease, pregnancy, and sleep apnea.

Hypertension Can Do Great Damage

It may seem as though a somewhat elevated blood pressure shouldn't be that big a deal - and this is true when the condition lasts for only a few months, as in pregnancy-induced hypertension. The real problem arises when blood pressure is elevated over a period of years or decades. Over such a time span, hypertension can cause significant damage to blood vessels that supply life-giving oxygen and nutrients to all parts of the body. The heart, brain, and kidneys, along with all other major body parts, can suffer irreparable harm from long-term hypertension.

It's important to remember that an unhealthy elevation in just one of the two pressures (systolic or diastolic) can have disastrous long-term health consequences. Isolated high systolic pressure, which is the most common form of high blood pressure in older adults, is thought by many to be a significant indicator of heart attacks and strokes in people middle-aged and older. Isolated high diastolic pressure is a strong risk factor for heart attacks and strokes, especially in younger adults.

Hypertension Is Big Business

With so many people having hypertension, the drug companies have introduced a plethora of medications to control it. Studies have shown that 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. While the majority of these drugs (including diuretics, calcium channel blockers, and ACE inhibitors) work well, they can have troublesome to potentially deadly side effects, including hyperglycemia (high blood glucose), tinnitus (constant ringing or buzzing in the ears), kidney damage, and heart failure.

Hypertension Can Be Controlled Naturally

For those who hesitate to use antihypertensive drugs for whatever reason, 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!), obesity control, and salt restriction - 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. Arginine, an amino acid that is vitally important for overall good health, may be a potent weapon in the fight against hypertension. 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.

So how does arginine work its wonders? The answer lies in its ability to produce nitric oxide (NO), a simple gas made up of nitrogen and oxygen that performs some amazing feats in the human body. In fact, NO is such an important molecule that the 1998 Nobel Prize in Medicine was given to three scientists for their pioneering research on its role in human physiology.*

*Paradoxically, nitric oxide is a free radical, a type of highly reactive molecule that is usually harmful to living tissues. Every rule has its exceptions.

Nitric oxide penetrates and crosses the membranes of almost all cells in the body, and it helps regulate many cellular functions. It is even involved in memory function. In blood vessels, NO is vitally important because it regulates the tone of the endothelium, the layer of smooth cells that line the inside of the vessels. If these endothelial cells become dysfunctional, they can cause spasms or constrictions of the blood vessels that can then lead to hypertension.

Arginine Reduces Blood Pressure in Healthy Adults

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

After only one week, the men on both 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 diet 2 or diet 3. Although the authors readily admit that the study had serious limitations (the short duration and the small number of subjects), they concluded that "the present study indicates that an approximately two-fold increase in dietary L-arginine intake had significant hemodynamic and metabolic effects in a group of healthy men."

Arginine Reduces Blood Pressure in Diabetics

People who suffer from diabetes have an increased risk for developing coronary artery disease, of which high blood pressure is often a significant component. Scientists are now looking at how arginine might help people with diabetes, in terms of both reducing their blood pressure and helping their bodies use insulin more efficiently.

A recent study examined the effects on blood pressure when arginine was given to six patients with type 2 (age-related) diabetes and hypertension.³ They received 3 grams of arginine every hour for 10 hours on either day 2 or day 3 of the study. On both of these days, their blood pressure was monitored for the same 10 hours. The results showed that the patients' systolic and diastolic pressures were significantly reduced only 2 hours after they started taking arginine.

As with the previously mentioned study, this one was small and needs to be reproduced on a larger scale before any firm conclusions can be drawn. However, since many scientists believe that endothelial dysfunction in the blood vessels is one of the reasons why diabetes is associated with a higher risk for cardiovascular disease, taking supplemental arginine, with its known beneficial effects on endothelial cells, seems to make sense.

Arginine Improves Insulin Sensitivity

One of the main physiological problems in type 2 diabetes is that the body's cells become increasingly resistant to the action of insulin. This is the hormone that helps cells take in glucose (the "fuel" the body needs to stay alive) from the blood. If insulin resistance develops, glucose is not transported into the cells as efficiently as it should be, and it builds up in the blood. That is why people with diabetes are often said to have high blood sugar - and it must be controlled. A recent study showed that arginine supplementation (9 grams daily) may help people with type 2 diabetes utilize glucose more efficiently by improving their insulin sensitivity.⁴

Arginine - Good for Sex!

Besides helping to control hypertension, arginine can also give a boost to one's sex life. Nitric oxide produced from arginine increases blood flow to the penis in men and to the clitoris in women. Because of this, men who take arginine often have stronger, firmer erections, while women can gain increased clitoral sensitivity. When you put these two together (so to speak), you can see why almost all major sexual supplements on the market today contain a hefty dose of arginine.

Arginine Helps Keep the Pressure Down

As our population grows ever older, conditions such as heart disease, cancer, and hypertension will affect more and more people. Fortunately, through a nutritious diet, regular exercise, and supplements such as arginine, there are natural, side-effect-free ways to stay in good physical shape and keep the pressures of life down.

References

1. Calvert, JF. Cardiovascular disease and hypertension. Clinics Fam Pract 2001;3(4):733-56.
2. Siani A, Pagano E, Iacone R, et al. Blood pressure and metabolic changes during dietary L-arginine supplementation in humans. Am J Hyperten 2000;13:547-51.
3. Huynh NT, Tayek JA. Oral arginine reduces systemic blood pressure in type 2 diabetes: its potential role in nitric oxide generation. J Am Coll Nutr 2002;5:422-7.
4. Piatti P, Monti LD, Vilsecchi G, et al. Long-term oral L-arginine administration improves peripheral and hepatic insulin sensitivity in type 2 diabetic patients. Diab Care 2001;24:875-80.

Dr. Rosick is an attending physician and clinical assistant professor of medicine at Pennsylvania State University, where he specializes in preventive and alternative medicine. He also holds a master's degree in healthcare administration.