Is red yeast rice hard on kidneys?

Red yeast rice supplement has the potential to cause liver damage, warn doctors in the journal BMJ Case Reports, after a 64-year old woman developed acute liver injury after six weeks of taking the supplement.

Red yeast rice is a supplement made by fermenting steamed rice with food fungus, and is often used to lower high cholesterol as an alternative to statin medication.

But it contains monacolin K, the same active chemical found in the cholesterol lowering drug lovastatin, and therefore carries the same risk of liver damage, say the authors.

In this particular case, a 64-year old woman was admitted to hospital with symptoms of hepatotoxicity (liver damage) six weeks after starting a 1200 mg per day of red yeast rice supplement to lower her cholesterol, due to being hesitant about taking statins.

For two weeks, the woman had been experiencing fatigue, bloating and feeling full sooner than usual. And her urine was darker, her stools were lighter, and she had recently developed jaundice.

She did not report any liver disease, blood transfusion, contact with anyone ill or recent travel. And apart from B12 injections for anaemia, she did not take any medication.

The woman was a non-smoker, drank two glasses of red wine every night, and had an active lifestyle.

A liver biopsy showed findings consistent with acute drug induced liver injury (DILI). While alcohol intake was considered and may have contributed to her disease, the nature and timeline of it suggests DILI was the cause, write the authors.

The woman was treated with steroids and her liver function was monitored weekly after she was discharged. She was advised not to use the supplement again.

This report refers to just one case, and more research is needed to establish any possible association and mechanism of toxicity. But several cases of red yeast hepatotoxicity have been previously documented, write the authors, and these have shown that recovery may take months after discontinuing.

“As this case demonstrates, red yeast rice supplement has the potential to cause severe adverse effects, such as acute liver injury,” say the authors. And they warn that these effects “are difficult to pre-empt, in part because the concentration of monacolin K in red yeast rice is not regulated.” As such, they call for more regulation of supplements to prevent harmful side effects.

“Supplements are not necessarily safer than prescription medications, and physicians and patients should research their adverse effect profile before using them or approving their use,” they conclude.

Red yeast rice naturally contains a cholesterol-lowering ingredient, but you won’t -- or shouldn’t -- get it from the supplements you buy. This active ingredient, monacolin K, is identical to the prescription medication lovastatin, so the FDA does not allow it in red yeast rice. Some products tested as recently as 2011 contained significant amounts of monacolin K, according to the National Center for Complementary and Alternative Medicine. This ingredient can cause side effects, including liver and kidney damage.

Red Yeast Rice

The reddish-purple color of the fungus Monascus purpurea explains its common name: red yeast. Red yeast rice is produced by mixing the yeast with rice and allowing it to ferment. For centuries red yeast rice has been used in traditional Chinese medicine. It’s also a dietary staple in Asian cuisine and used as a flavoring and coloring agent in fish and meat, according to “Alternative Medicine Review.” In the United States it’s primarily sold as a supplement, but FDA regulations prohibit red yeast rice supplements from containing more than a trace amount of the active ingredient.

Active Ingredient

Monascus purpurea naturally contains substances called monacolins. While nine different monacolins have been identified, one of them -- monacolin K -- is the same active ingredient used in the prescription medication lovastatin, according to "Alternative Medicine Review." Lovastatin lowers levels of cholesterol by slowing down its production, notes MedlinePlus. The amount of monacolins in red yeast rice products varies according to the strain of yeast used and the way it's cultured. The strains used to make culinary red yeast rice and some supplements result in little to no monacolins, according to NCCAM.

Side Effects

Red yeast rice is considered safe because it should not contain the active ingredient, but supplements may still cause heartburn, gas and headaches, according to MedlinePlus. However, you should not take supplements longer than three months because long-term side effects have not been determined. If the red yeast rice you consume contains monacolin K, it can have the same risks as prescription lovastatin, which includes breaking down muscle tissue, liver damage and kidney failure. Seek medical attention immediately if you experience fever, unusual tiredness or weakness, dark colored urine, muscle pain, pain in the upper abdomen or yellowing of the skin or eyes.

Warnings

Product quality is a concern because some red yeast rice brands don’t contain any monacolin K, while others contain enough to cause serious side effects. Women who are pregnant or breastfeeding and anyone with liver or kidney disease should not consume red yeast rice. If you take any prescription medications, especially any that might harm your liver, talk to your physician before taking red yeast rice supplements. Do not mix acetaminophen, grapefruit juice, alcohol or niacin supplements with red yeast rice. Another potential risk is that it can contain a kidney-damaging poison called citrinin if the red yeast is not fermented properly, according to MedlinePlus.

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