Red yeast rice, or RYR, is a unique supplement or ingredient created by culturing and fermenting rice with specific strains of yeast.
The fermented product includes bioactive compounds that have a physiological effect and a red color that results from the fermentation process.
RYR has gained attention for its role in cholesterol reduction and cardiovascular disease risk reduction.
When whole, it contains carbohydrates, protein and a small amount of fat as well as pigments, sterols and isoflavones.
The exact composition of RYR depends on the type of rice and yeast. There’s a degree of variability in function and safety.
Several types of bioactive compounds known as monacolins are found in RYR. The most effective of these is monacolin K, which is structurally identical to the statin lovastatin. As with its pharmacological twin, monacolin K inhibits cholesterol production in the liver. But monacolin K from RYR has a wide range of efficacy, which makes its effects less predictable than a statin.
Clinical studies have been conducted on RYR’s lipid-lowering effect. A review of 20 clinical trials found that it had an LDL cholesterol-lowering impact similar to low-intensity, low-dose statins such as pravastatin, simvastatin and lovastatin. A reduction of 15% to 25% was reported in subjects of different ethnicities, demonstrating the benefits of this supplement.
Other markers of cardiovascular disease health have been measured, too, including triglycerides, HDL-cholesterol, C-reactive protein, flow-mediated dilation and pulse-wave velocity. All of these improved with RYR supplementation, though the magnitude of improvement varied among studies.
The federal Food and Drug Administration issued warnings in 2007 and 2013 regarding the use of RYR that focused on its safety, effectiveness and a lack of product standardization. Because the efficacy of RYR varies depending on the product, the cholesterol-lowering benefit also varies.
One disadvantage to RYR is the presence of potentially harmful compounds like citrinin, which can harm kidney function and impair fertility. So if you’re considering RYR supplements, look for one that’s certified as citrinin-free.
Clinical research has settled on effective doses of three to 10 milligrams of monacolin K from RYR per tablet.
RYR and RYR extract are commonly found as dietary supplements. These can be combined with other nutritional and bioactive compounds that aid in cholesterol lowering such as soluble fiber, plant sterols, probiotics and phytochemicals. Talk with your doctor before taking RYR.
Environmental Nutrition is a newsletter written by experts on nutrition.
