Garlic: Herbal Medications, What Works

Dr. Kenneth R. Pelletier - The Best Alternative Medicine

Corporate Health Improvement Program (C H I P)

| print page

Garlic (Allium sativum) is recognized in traditional medicine worldwide as a valuable medicinal herb. In the United States and Western Europe, garlic has become one of the most popular substances for reducing cardiovascular risk factors. This medicinal application is partly based on a large number of clinical studies.

Garlic is used for reduction and stabilization of blood pressure, blood sugar, and blood lipids. It also has anticlotting, antioxidant, antimicrobial, antifungal, and antiprotozoal activity, and boosts immunity.

By 1993, at least 1,088 scientific studies dealt with garlic's medicinal effects, for both healthy people and ill people. Garlic's medicinal properties depend on its principal active constituent, allicin, which has a strong odor and is unstable under many conditions. Many people object to the bad breath caused by garlic, but deodorized garlic preparations do not have the same allicin-producing ability, and are less valuable medically. Also, cooking destroys most of garlic's medical benefits. Carefully dried garlic powder preserves the alliinase activity, but the powder should be ingested in enteric-coated tablets to protect it from inactivation by stomach acid.

Most of the clinical trials on garlic have studied its effect on lowering blood lipids, especially total cholesterol and low-density lipoproteins (LDL).

Forty studies yielded a mean decrease of serum cholesterol of 10.6 percent. In another meta-analysis of studies by Warshafsky, researchers concluded that garlic, at a dosage of about one-half to one clove a day (or 600-900 mg) was able to reduce total serum cholesterol levels by about 9 percent.
Other clinical studies have looked at the effect of garlic on blood pressure, as well as its antibiotic, anticancer, antioxidant, and immunomodulatory effects. Although research appears promising in these areas, the evidence is not as strong as it is for hypolipidemic activity.
Epidemiological studies have suggested that garlic (as well as other members of the genus Allium, including onions, leeks, shallots, chives, and wild garlic) can reduce the risk of certain types of cancer. Statistical studies have correlated garlic consumption with low incidence of cancer in Europe, Egypt, India, China, and in some Third World countries.
Clinical research on garlic's anticancer properties has generally involved Kyolic^®, an odorless, aged garlic extract from Japan. This preparation, however, is less effective for cardiovascular problems. In a study by Steiner, it yielded reductions in total cholesterol of about 6 to 7 percent. While these results are positive, they do not compare with the degree of blood lipid reduction that has been achieved with standardized powdered garlic preparations. Moreover, the amount of garlic given in the Kyolic study was 7.2 grams a day, a relatively large and costly dosage.

Research seems to substantiate claims for garlic's ability to reduce cardiovascular risk factors, but the precise mechanism remains unknown. Perhaps future well-designed research will confirm garlic's anticancer actions.

Return to Excerpts List

From THE BEST ALTERNATIVE MEDICINE: WHAT WORKS? WHAT DOES NOT? by Dr. Kenneth R. Pelletier.

Reprinted by permission of Simon & Schuster, Inc., New York, New York.

Return to Top