The three products involved in the official website of Kobayashi Pharmaceutical Company are red yeast cholesterol granules, nattokinase granules and cholesterol-lowering health auxiliary granules, all of which contain red yeast rice ingredients and can lower cholesterol as the main selling point, and these three products can be purchased in ordinary drugstores in Japan. On a number of e-commerce platforms in China, there are also official stores of Kobayashi Pharmaceutical that sell its products.
What is Red Yeast Rice?
Red yeast rice is a red yeast rice made by the purple Monascus parasitic of the Aspergillus family fungus on the seed kernel of gramineous rice, which is an irregular granular rice grain, purple red or dark red on the surface, crisp and pink. Red yeast rice is sweet in taste, warm in nature, and belongs to the liver, spleen, and large intestine meridians, and has the effect of activating blood and removing blood stasis, strengthening the spleen and eliminating appetite, and can be used for postpartum stasis and abdominal pain, fall injury, dietary stagnation and abdominal distention.
It is safe for the red yeast inherently, but the fermentation process of monascus to produce red yeast may produce a secondary product called citrinin (also known as citrin), and toxicological studies have found that citrinin has strong nephrotoxicity, which can lead to kidney enlargement, tubular dilation and epithelial cell necrosis. Toxicological studies have shown that citrinin can induce cell mutations and lead to malignant tumors in addition to neurotoxicity, hepatotoxicity and nephrotoxicity.
So what is citrin?
Citrinin is a mycotoxin, mainly produced by Penicillium, Aspergillus and Monascus, many foods, feeds and Chinese herbal medicines are easily contaminated with citrinin, causing certain harm to human health, but its toxicity mechanism has not been clarified, and there is a lack of sufficient data for its risk assessment. Citrinin is often found together with another mycotoxin, ochratoxin A, and the two can have a synergistic effect to enhance its toxic side effects and become one of the causes of endemic kidney disease.
What is the limit of citrinin?
The mainland limits citrinin to red yeast pigment to 0.04mg/kg and monascus yellow to 1.0mg/kg, but there are no limits to red yeast rice products such as solid-state fermented red yeast rice. In addition, the limit standard of citrinin in health foods made from red yeast rice in mainland China is 0.05mg/kg.
Kobayashi Pharmaceutical's three health products containing red yeast rice are what causes consumers' health problems, Kobayashi Pharmaceutical currently says that it is not citrin, and is jointly investigating with university laboratories. Red yeast rice is a fermented traditional Chinese medicine, and the traditional fermentation process relies on changes in natural conditions, making it difficult to obtain stable product quality.
The modern fermentation process has strict specifications and quality control, and it needs to be produced in a workshop that meets GMP standards, accurately control the temperature and humidity in the fermentation process, and avoid secondary pollution by external microorganisms and other substances. Moreover, with the development of the food industry, the process of controlling the content of citrinin in Monascus is relatively mature, and the risk is generally within a controllable range.
Therefore, for the red yeast rice and its products produced by regular manufacturers, they can be eaten with confidence after standard testing.
Reviewer: Mei Qinghua, Director of the Department of Pharmacy, Guangdong Second People's Hospital
Author: Liang Ying, Second People's Hospital of Guangdong Province