The Beni-Koji scandal and Japan's unique health food system
Authors: Takanao Hashimoto, Akihiko Ozaki, Hayase Hakariya, Kenzo Takahashi, Tetsuya Tanimoto
Journal: The Lancet (2024)

As of April 7, 2024, in Japan, supplements containing red yeast rice (Beni-Koji) provided by Kobayashi Pharmaceutical have been reportedly linked to approximately 3000 health hazard events, including 212 patients treated in hospital and five deaths, due to acute renal failure resembling Fanconi syndrome.1Kobayashi PharmaceuticalRecall of products containing Beni-Koji.https://www.kobayashi.co.jp/notice/index.htmlDate accessed: April 6, 2024Google Scholar The supplements' health hazards were predominantly associated with the consumption of products manufactured after September, 2023, and Japanese mass media assumed that these adverse events were attributable to puberulic acid, a compound produced by blue mould, thereby suggesting contamination at the production facility as a potential source.2Kobayashi Pharmaceutical's "red yeast rice" problem: two substances that are not normally found in addition to puberuric acid have been confirmed. NHK News, April 19, 2024https://www3.nhk.or.jp/news/html/20240419/k10014427361000.htmlDate accessed: May 1, 2024Google Scholar Furthermore, the mycotoxin citrinin produced by Beni-Koji is also considered a substance that could induce nephrotoxicity, but the strain Monascus pilosus, used by Kobayashi Pharmaceutical in Beni-Koji products, reportedly did not produce citrinin.3Higa Y Kim YS Altaf-Ul-Amin M Huang M Ono N Kanaya S Divergence of metabolites in three phylogenetically close Monascus species (M pilosus, M ruber, and M purpureus) based on secondary metabolite biosynthetic gene clusters.BMC Genomics. 2020; 21: 679Crossref PubMed Scopus (13) Google ScholarIn 1991, Japan established the Foods for Specified Health Uses system; to simplify the assessment process and to expand the health food market, the Foods with Function Claims system was established in 2015—products containing Beni-Koji are classified as Foods with Function Claims.4Consumer Affairs AgencyGovernment of JapanAbout foods with health claims (in Japanese).https://www.caa.go.jp/policies/policy/food_labeling/foods_with_health_claimsDate: Dec 5, 2023Date accessed: May 1, 2024Google Scholar The sales of food products within the Foods with Function Claims system has increased from about US$1·43 billion in 2018 to about $3·57 billion in 2023.5Ministry of Finance: The FinanceGrowth potential of health foods in Japan.https://www.mof.go.jp/public_relations/finance/202402/202402p.pdfDate accessed: April 17, 2024Google Scholar The current Beni-Koji supplements' health consequences have exposed drawbacks inherent to the system. First, the current law does not mandate that the manufacture of plants for Foods with Function Claims obtain Good Manufacturing Practice certification, as these products are not categorised as medicine. Second, the system does not have sufficient provisions for third-party organisations, other than manufacturers, to collect and disseminate information on health hazards. The absence of a unified public consultation system for health foods and supplements probably contributed to the delayed identification of the problem. Third, there is insufficient transparency of the research papers that underpin the Foods with Function Claims; for example, an article supporting Beni-Koji products was authored by an employee of the Kobayashi Pharmaceutical Research and Development Center.3Higa Y Kim YS Altaf-Ul-Amin M Huang M Ono N Kanaya S Divergence of metabolites in three phylogenetically close Monascus species (M pilosus, M ruber, and M purpureus) based on secondary metabolite biosynthetic gene clusters.BMC Genomics. 2020; 21: 679Crossref PubMed Scopus (13) Google Scholar To rebuild trust with Japanese citizens, as well as the international community, it is crucial to extend Good Manufacturing Practice regulations to health foods and to establish an information collection and dissemination system in line with international standards.6US Food and Drug AdministrationCurrent Good Manufacturing Practices (CGMPs) for food and dietary supplements.https://www.fda.gov/food/guidance-regulation-food-and-dietary-supplements/current-good-manufacturing-practices-cgmps-food-and-dietary-supplementsDate accessed: April 7, 2024Google Scholar Furthermore, it is important to create an environment in which consumers can obtain accurate product quality information and manufacturing processes and efficacy are under systematic regulation. It is imperative that the economic benefits of health food products should not take precedence over safety considerations. This principle is akin to the stringent safety regulations that govern medical products. AO receives consulting fees from Medical Network Systems, unrelated to this Correspondence; receives honoraria from Kyowa Kirin, Taiho Pharmaceutical, Pfizer Japan, and Becton, Dickson and Company, also unrelated to this Correspondence; has been granted funds for his research on financial relationships between the health-care industry and health-care professionals by the Daiwa Japan Anglo-Japan Foundation; and serves as a committee member for the Japan Society for Medical Education, focusing on professionalism as a physician. TT receives personal fees from Medical Network Systems and Bionics, unrelated to this Correspondence. All other authors declare no competing interests.