Nearly 500 people hospitalised in Japan after taking red yeast supplements

Kobayashi Pharmaceutical’s beni koji dietary supplements have been linked to 175 deaths so far

Nearly 500 people in Japan have been hospitalised after consuming health supplements containing red yeast rice, the country’s health ministry said on Tuesday.

The dietary supplements from Kobayashi Pharmaceutical Co, billed as helping to lower cholesterol, have been under investigation since being linked to five deaths in March. The supplements have beni koji which contains Monascus purpureus, a species of red mould used as a food colouring.

In all, the supplements have been linked to 175 deaths. The exact causes of death haven’t been confirmed but the health and welfare ministry told Reuters in April that “beni koji may be the cause”.

As many as 492 people have been hospitalised as of Sunday, 291 of them with kidney diseases, the Japan Times reported.

Kobayashi, based in Osaka, has been making beni koji products for years, with about one million packages sold in the last three fiscal years. But there has been a problem with the supplements produced in 2023.

The firm has said it found potentially toxic puberulic acid that could be produced by blue mould penicillium in beni koji materials produced between April and October last year at its Osaka factory.

It has recalled the supplements, which could be purchased without a doctor’s prescription, and launched an investigation.

The government has criticised the company for taking two months to announce the health impacts of its products. Kobayashi began recalling products on 22 March after receiving reports of kidney ailments.

The firm has since apologised and issued a statement asking consumers to not consume the supplements. “Please stop taking our products and please do not use them in the future,” it said.

“We will fully cooperate with the investigation so that we can resolve the problems as early as possible,” the head of Kobayashi’s investor relations, Yuko Tomiyama, told reporters in April.

The products are consumed outside Japan as well, with Taiwan reporting cases of acute renal failure. The island’s food and drug administration is investigating three "unexpected health reactions" that it said may be linked to imported materials from Kobayashi, the official Central News Agency reported.

A Chinese consumers association has urged people to stop using the supplements, state media reported.

The Independent has reached out to Kobayashi Pharmaceutical Co for a comment.