NEW YORK (Reuters Health) - The content of the red yeast rice supplement that manufacturers claim reduces cholesterol, varies dramatically depending on the brand, with some products containing far less of the active ingredient than has been shown scientifically to be effective, and other containing one or more contaminants, new analysis by ConsumerLab demonstrates.
Four out of the 10 products ConsumerLab tested contained a toxic substance called citrinin.
“Our research indicates that consumers need to be very careful when choosing red yeast rice products, because we found a 100-fold variation in the amount of active compounds across the products,” Dr. Tod Cooperman, the president of the White Plains, New York-based independent testing company, told Reuters Health.
Red yeast rice is produced by fermenting yeast with rice, and contains lovastatin, the active ingredient in the prescription drug Mevacor, a member of the class of drugs known as statins used to treat high cholesterol. Studies have shown that red yeast rice may be effective in lowering low-density lipoprotein (LDL), or “bad” cholesterol. However, comparisons can not be made because of the differences in the compound.
The Food and Drug Administration have no control over herbal products, which don’t have to reveal how much lovastatin they contain.
ConsumerLab checked the lovastatin content of 10 red yeast rice products, and also checked for contamination with citrinin, which can be produced in the fermentation process. This substance is known to be toxic in animals, and may also be harmful to humans.
Although all of the products were labeled as containing 600 milligrams of red yeast rice, their lovastatin content varied from 0.1 milligrams, found in Walgreen’s Finest Natural Red Yeast Rice, to 10.6 milligrams. The four least potent formulations, including the Walgreen’s product -- contained citrinin. Other contaminated products included Natural Balance Red Yeast Rice Concentrated Extract, Solaray(r) Red Yeast Rice, and VegLife(r) 100% Vegan Red Yeast Rice.
People who want to get the cholesterol lowering benefits of red yeast rice should consume enough to get 5 to 15 milligrams of lovastatin, based on their initial cholesterol level, according to Cooperman.
People would be wise to steer clear of potentially contaminated products, he added, and should also know that red yeast rice can cause many of the side effects seen with statin drugs, including muscle damage. Anyone thinking about taking the supplement should talk with their physician first, he advised.