What is Red Fermented Rice (Red Yeast Rice)?

Red fermented rice (also known as red yeast rice, hong qu) is produced by fermenting rice with the fungus of the genus Monascus, most commonly Monascus purpures (see Fig). Different from red rice, red fermented rice is not consumed as a staple. It has been used as flavour enhancer, for meat preservation and wine brewing in Asia for centuries. Traditionally, red fermented rice is used in furu, rice wine, and some Chinese cuisines.

Depending on the Monascus strains used and the fermentation conditions, various pigments, which give the distinct colour to red fermented rice, and some pharmacologically active substances (e.g. monacolin K / lovastatin) may be formed by Monascus spp.

1. In the Asian region, red fermented rice has a long history of use as food ingredients. Tests performed by the US Food and Drug Administration indicate that red fermented rice sold as a food product contains no or only traces of monacolin K. There is no evidence showing any safety issues upon normal consumption of these traditional food products.
2. Monacolin K produced during Monascus fermentation is chemically identical to the active ingredient lovastatin in the cholesterol-lowering drug. Consumption of products containing monacolin K may affect blood cholesterol levels and causes the same types of side effects (e.g. liver toxicity and muscle problems) and drug interaction as lovastatin.
3. In Hong Kong, according to the information from the Pharmacy and Poisons Board of Hong Kong, products containing lovastatin with a daily dose of 10mg or more would be regarded as pharmaceutical product, which shall be registered as prescription only medicine by the Pharmacy and Poisons Board of Hong Kong before they could be sold or distributed in Hong Kong.

A recent report points out that consumption of red yeast rice containing products produced by Kobayashi Pharmaceutical Co. Ltd. of Japan (the Company) may lead to health problems (e.g. kidney diseases). The Company have found that these products may contain unexpected ingredients and has alerted to stop selling and using the products. An investigation by the Ministry of Health, Labour and Welfare of Japan is ongoing.

Please click on the hyperlink below for the information about the use of red fermented rice in Chinese medicine and Western medicine:
https://www.drugoffice.gov.hk/eps/upload/eps_news/53149/EN/1/Red%20Yeast%20Rice_en.pdf

Advice to Public

• Red rice should not be confused with red fermented rice.
• Red rice can form part of a balanced diet and is safe for human consumption.
• Not to consume the red fermented rice products produced by Kobayashi Pharmaceutical Co. Ltd. of Japan if one has purchased any.
• Consult medical professionals if one intends to consume red fermented rice products for its cholesterol-lowering effects, or one feels unwell after consuming them.