Japan’s Ministry of Health, Labor and Welfare has confirmed what people are worried about: Osaka-based manufacturer’s red yeast rice products did contain elements that might have contributed to health problems and deaths of consumers.
Puberulic acid produced by blue mold caused kidney damage, in relation to a series of health issues reported by consumers of Kobayashi Pharmaceutical’s red yeast rice supplements earlier this year, the ministry announced.
The ministry reported on May 28 that the cultivation of blue mold found in the cultivation chambers and tanks at Kobayashi Pharmaceutical’s factories in Osaka and Wakayama prefectures led to the production of the acid.
As of May 27, five people had died after taking one of three types of supplements that have been recalled by Osaka-based Kobayashi Pharmaceutical, while 281 others had been hospitalized, according to the health ministry.
Research by the Japanese Society of Nephrology confirmed that some of the patients suffered from Fanconi syndrome, a condition that prevents the absorption of electrolytes and other substances, characterized by the deterioration of tubules in the kidneys.
Experiments conducted by the ministry found that puberulic acid caused necrosis and other damage to the kidneys of rats. The ministry will continue to investigate the link between the blue mold found at the factories and the health issues caused by the supplements.
The Japanese government plans to hold a meeting of relevant cabinet ministers to formulate a policy in response to these findings.
In addition to puberulic acid, two other compounds were found in Kobayashi Pharmaceutical products manufactured between June and August 2023, a period during which many health issues were reported.
The effects on human health of these two additional compounds are not yet known.
The ministry said it suspects these compounds were also produced as a result of blue mold contamination during the cultivation process.
On May 28, Kobayashi Pharmaceutical issued a statement apologizing for the significant distress and anxiety caused. The company pledged to fully cooperate with the investigation and to make every effort to restore public trust.
Kyo Taniguchi, director of Taniguchi International Clinic in Osaka, said that even in the absence of contaminants, red yeast rice itself carries a risk of causing kidney dysfunction.
Writing in the Mainichi Shimbun, one of Japan’s leading newspapers, on April 8, Taniguchi noted that several countries have issued bans or safety warnings regarding red yeast rice use since the 2010s.
Taniguchi also noted that the efficacy and safety of red yeast rice must be regarded as equivalent to pharmaceutical drugs. Its primary ingredient, monacolin K, is identical to the active component in the cholesterol-lowering drug lovastatin, he explained.
While lovastatin is not approved in Japan, it is prescribed in other countries for cholesterol management. However, lovastatin can cause side effects, including renal dysfunction, and can sometimes lead to severe complications, Taniguchi said.
Since the early 2010s, the safety of red yeast rice has been scrutinized worldwide. Switzerland has declared its sale illegal, Germany has issued warnings against its consumption, and both France and the European Union have expressed safety concerns, he noted.
In summary, Taniguchi stated that while red yeast rice supplements are marketed for their cholesterol-lowering benefits, their risks — particularly concerning kidney health — cannot be ignored.