- What is red yeast rice?
- What is the present status of red yeast rice?
- What are the different preparations of red yeast rice?
- What is the composition of HypoCol and Cholestin?
- How effective are HypoCol, Cholestin, and Xuezhikang in lowering lipids?
- How safe are red yeast rice products?
- Are there any side effects and precautions in consuming red yeast rice products?
- Who are suitable candidates for red yeast rice products?
- Who are not suitable candidates for red yeast rice products?
What are the different preparations of red yeast rice?
There are three major preparations of red yeast rice:
- Cholestin or Hypocol, and
Zhitai is produced by the fermentation of a mixture of different strains of Monascus purpureus on whole grain rice. Zhitai contains mainly rice and yeast, but is mostly rice by weight.
Cholestin or HypoCol
Cholestin or HypoCol is produced by the fermentation of selected strains of Monascus purpureus, using a proprietary process that produces a certain concentration of monacolin K (monacolin K is lovastatin, which is believed to be the major cholesterol-lowering ingredient).
Xuezhikang is produced by mixing the rice and red yeast with alcohol and then processing it to remove most of the rice gluten. Xuezhikang contains 40% more cholesterol-lowering ingredients than Cholestin or Hypocol.
In Singapore, red yeast rice is available as Hypocol (NatureWise, Wearnes Biotech & Medicals (1998) PTE LTD).
What is the composition of HypoCol and Cholestin?
At one time, Cholestin contained red yeast rice, and at that time scientists at Pharmanex and the UCLA Center for Human Nutrition analyzed the properties Cholestin. The composition by weight is:
- starch (73%),
- protein (5.8%)
- moisture (3%-6%),
- unsaturated fatty acids (1.5%),
- monacolins (0.4%),
- ash (3%), and
- trace amounts of calcium, iron, magnesium, and copper.
There are no additives, preservatives, heavy metals, or toxic substances, such as citrinic acid.
In 1977, Professor Endo in Japan discovered a natural cholesterol-lowering substance that is produced by a strain of Monascus yeast. This substance inhibits HMG-CoA reductase, an enzyme that is important for the production of cholesterol in the body. Professor Endo named this substance moncacolin K. Since then, scientists have discovered a total of eight monacolin-like substances that have cholesterol-lowering properties.
Monacolin K is lovastatin, the active ingredient in the popular statin drug, lovastatin (Mevacor), which is used for lowering cholesterol. Lovastatin also is believed to be the main cholesterol-lowering ingredient in HypoCol. The lovastatin in Mevacor is highly purified and concentrated, the lovastatin in HypoCol is not. Thus, they contain much lower concentrations of lovastatin than Mevacor. For example, each 600-mg capsule of Cholestin contains less than 2.4 mg of lovastatin (when this ingredient was contained in the product), whereas tablets of Mevacor contain 10 mg or more of this ingredient.
Because none of the components are purified and concentrated, HypoCol and Cholestin (marketed outside of the US) contain a mixture of the eight yeast-produced monacolins, unsaturated fatty acids, and certain anti-oxidants. Some scientists believe that these other monacolins, unsaturated fatty acids, and anti-oxidants may work together favorably with lovastatin to enhance its cholesterol-lowering effects, as well as its ability in lowering triglycerides and increasing HDL cholesterol. (HDL is considered the "good" form of cholesterol since high levels of HDL cholesterol protect against heart attacks.) Further studies in animals and humans will be necessary to test these theories.