BAKERSFIELD, Calif. -- For centuries, the Chinese have used extracts from red yeast rice to treat patients who have circulation problems.

It turns out the Chinese were onto something. The active ingredient in red yeast rice is lovastatin, which is used in the cholesterol-lowering drug Mevacor.

On Monday, researchers from China reported that red yeast rice supplements lowered repeat heart attack risk by 45 percent in a study of nearly 5,000 patients who already had heart attacks.

Over a five-year period, those who took red yeast rice extract also had a one-third lower risk of bypass surgery or angioplasty, death from heart disease and death from any cause.

However, researchers said that the supplement used in the study was not the same type sold in U.S. health food stores. In fact, last year the FDA warned consumers not to buy three types of red yeast rice products containing lovastatin.

The FDA is concerned that without a doctor prescribing the drug, consumers may not get an effective dose, but also may experience side effects and harmful interactions with other medications.