Red yeast rice can produce citrinin, a toxic metabolite that causes kidney disease, which is speculated to be the cause of five Japanese deaths after taking dietary supplements.
This conjecture was made by some experts after Japan recorded three more deaths related to Kobayashi pharmaceutical company’s beni-koji red yeast rice functional food, bringing the total number of deaths to 5. Number of cases Hospitalizations to date are 115. The pharmaceutical company has voluntarily recalled the product from store shelves. Japan also recalled more than 40 products containing beni-koji from other companies, including miso paste, crackers and vinegar sauce.
Health officials recorded that the first person to die ordered 35 packs of Beni Koji Cholesterol Help from February 2021 to February 2024. Symptoms in this person and others include changes in urine color, swelling of limbs, fatigue and impaired kidney function.
What is Beni-koji?
Beni-koji has long been used as a food coloring, in the production and processing of fermented beverages. It is derived from red rice brewed with the fungus Monascus purpureus.
The fermentation process begins with steaming the red rice, then inoculating it with Monascus purpureus spores and leaving it in a private place under controlled conditions. Over time, the rice turns bright red, a red pigment produced by fungi. This is also the origin of the name “beni”, which means red.
According to Associate Professor Yumiko Yoshizaki of Kagoshima University, an expert in fermented food research, Japanese researchers discovered a cholesterol-lowering ingredient, called monacolin K, from mold in the 1970s.
In recent years, this substance has attracted attention as an ingredient in health supplements. Beni-koji is high in monacolin K. In addition, this type of yeast rice also contains antioxidants, amino acids and beneficial enzymes, bringing overall health and happiness.
The unique flavor and health benefits of beni-koji make it a sought-after ingredient in Japanese cuisine and many parts of the world. Chefs often use it to cook miso sauce, soy sauce, and saka wine.
Risks from beni-koji
Despite its health benefits, beni-koji fermentation can produce citrinin, a toxic metabolite that causes kidney disease. Citrinin is a mycotoxin, produced by species of the genera Aspergillus, Penicillium and Monascus. Citrinin is formed after harvest, appearing mainly in stored grains. Often, it is found together with other mycotoxins, especially ochratoxin A, which causes kidney disease.
In addition to nephrotoxicity, citrinin is also associated with programmed cell death (apoptosis) through oxidative stress. Many different animal experimental models show that citrinin and ochratoxin A can poison the liver, lungs, cells, immune system, and cause cancer.
Japan’s Food Safety Commission said Europe has reported some people’s health problems due to the use of dietary supplements containing beni-koji. The EU once set a standard limit for citrinin in healthy foods.
Responding to this report, Kobayashi tested the ingredients in beni-koji and concluded it did not contain citrinin. However, they detected an unknown substance, possibly the yeast rice product produced other unwanted ingredients.
Currently, Japanese health officials have not concluded the cause of 5 deaths and more than 100 people hospitalized after taking functional foods.