NEW YORK (Reuters Health) - For centuries, people have relied on the power of garlic for everything from enhancing athletic performance to thinning blood. The herb has even been found in tombs from ancient Egypt and Rome.

In recent times, researchers have uncovered what is perhaps garlic's most important effect: lowering the risk of heart disease.

``The published studies in their aggregate suggest that appropriate usage of allium derivatives from garlic may potentially play a role in the maintenance of optimal cardiac function,'' according to Michelle H. Loy and Dr. Richard S. Rivlin of Memorial Sloan-Kettering Cancer Center and Weill Medical College of Cornell University in New York.

Their review is published in a recent issue of Nutrition in Clinical Care, published by Tufts University.

The researchers looked at studies investigating the effect of garlic on risk factors for heart disease. Several studies suggest that garlic may lower total cholesterol, LDL (''bad'') cholesterol and blood pressure. It may also help keep blood thin, reducing the risk of blood clots and stroke, and function as an antioxidant.

Antioxidants neutralize the effect of free radicals, molecules that are natural byproducts of metabolism that damage DNA and lead to chronic disease such as heart disease, as well as aging.

However, not all studies have demonstrated a link between garlic and a lower risk for heart disease, the authors note. For this reason, they call for further studies investigating how garlic might help reduce cholesterol, specific compounds that might reduce heart disease risk, and effective doses of these compounds.

``Further research is needed to examine the structure-function relationships of the various allium derivatives of garlic, the amounts in foods and supplements required for efficacy, and the possible effects of combining garlic with other nutrients and medications,'' Loy and Rivlin conclude.

SOURCE: Nutrition in Clinical Care 2000;3:145-152.

(From Yahoo)