Many Americans take statins daily, but adverse effects—including muscle pain, fatigue, and gastrointestinal upset—limit their use in 10% to 15% of patients, according to an international lipid expert panel.1 One report has estimated that an additional 12.8 million adults would be eligible for statins based on the 2013 American Heart Association/American College of Cardiology lipid guidelines.2 Red yeast rice (RYR) has been used in China for cardiovascular disease and has been recommended for patients who cannot tolerate statins.
RYR is made from rice fermented by Monascus purpureus yeast. The supplement contains monacolin K (MonK), which is structurally identical to lovastatin and responsible for its lipid-lowering properties, probably by inhibiting 3-hydroxy-3-methylglutaryl-coenzyme A (known as HMG CoA) reductase. Average dosing of RYR ranges from 1,200 mg to 4,800 mg daily or 5 mg to 24 mg daily of MonK.
A 2015 systematic review evaluated 20 published studies of RYR to assess its lipid-lowering ability and adverse effect profile.3 Studies were conducted for at least 4 weeks and compared an RYR product with placebo, a low-dose statin, or another drug. The RYR products contained between 2.4 mg and 24 mg of MonK, with the most common dosage being 10 mg of MonK daily. More than 6,600 individuals were included in the studies, and about 70% were from the Chinese Coronary Secondary Prevention Study (CCSPS). Only a few studies were conducted outside of China.
The study durations ranged from 2 months to 6 months, except for the CCSPS, which was more than 3 years. Most studies used surrogate markers such as lipid values as the primary outcome, but CCSPS included reduction in cardiovascular events.
According to the review, RYR was superior to placebo in lowering LDL cholesterol (LDL-C), with an average decrease between 19 mg/dL and 62 mg/dL. HDL cholesterol increased by 3 mg/dL, and triglycerides decreased by 23 mg/dL.
In addition, small, short-term studies comparing RYR (MonK 10 mg daily) to simvastatin 10 mg, pravastatin 40 mg, and lovastatin 20 mg daily did not identify a difference in LDL-C lowering.
RYR was well tolerated, with muscle symptoms ranging from 0% to 23.8% for patients receiving RYR versus 0% to 36% for patients in the control groups. One of the included studies investigated the incidence of myalgia from RYR and pravastatin 40 mg daily in 43 patients with a history of statin intolerance. Patients taking the supplement had a lower risk of developing symptoms.
A 2014 review by Consumer Labs found wide variability in the amount of lovastatin-like compounds in commercially available RYR products.4 One product was identified to contain 1.6 mcg of citrinin per daily serving; this compound is produced by yeast and is a nephrotoxin in animals.4 Some RYR products may be significantly more expensive than generic statins. Most important is that the long-term efficacy of RYR on cardiovascular outcomes is unknown, although xuezhikang, the RYR extract used in CCSPS, demonstrated efficacy.
Statins are commonly prescribed to prevent heart attacks and strokes. Although statins are safe, many patients have symptoms such as muscle aches. RYR lowered cholesterol similar to low-dose statins in short-term trials with products containing MonK 10 mg. Whether the supplement actually prevents heart attacks and strokes is unknown, especially among Americans from diverse backgrounds.
RYR should not be used by pregnant women or those who may become pregnant. In selecting an RYR product, patients should be aware that the content of monacolins is commonly not reported on the label and may vary significantly. Patients also should be aware of the potential presence of citrinin.