A part of traditional Chinese medicine, red yeast rice is used as a health supplement. It contains monacolins, which are naturally occurring substances believed to limit the body’s production of cholesterol. It is also thought to benefit the stomach and spleen, as well as treat indigestion and diarrhea, and improve blood circulation.
Red yeast rice is created when monascus purpureus, a red yeast, is fermented over rice. One of the monacolins it contains, monacolin K, is structurally the same as mevinolin and lovastatin, two cholesterol-lowering drugs. Because of this, people taking red yeast rice can experience the same side effects and drug interactions they would potentially experience by taking such prescription medicines. Some potential problems associated with taking red yeast rice include low blood pressure, an increased risk of bleeding and a negative effect on blood sugar levels, the immune system and the nervous system. Because of these and other potential risks, the Food and Drug Administration issues warnings about all red yeast rice supplements and products containing monacolin K or lovastatin.
In addition to being made into a supplement, red yeast rice is a common part of Chinese cuisine. The product is also used as an additive, preservative and food coloring, as well as an ingredient in fish paste and rice wine.