Red yeast rice appears to lower blood cholesterol and triglyceride levels, but it is not certain whether these products are safe to use.
Red yeast rice is a traditional Chinese medicinal product that also has culinary uses. It is made by culturing rice with specific strains of yeast. It is also marketed as a dietary supplement to reduce cholesterol and other fats in the blood. One of its constituents, monacolin K, also known as lovastatin, is an active ingredient in the cholesterol-lowering drug, Mevacor®. The drug works by inhibiting an enzyme essential for the creation of cholesterol in the body. Therefore, it is assumed that red yeast rice works through a similar mechanism.
Even though red yeast rice appears to reduce blood fats, it is not certain whether these products are safe. Some may contain a harmful contaminant or have side effects similar to certain cholesterol-lowering drugs. There have also been several case reports of adverse effects, so patients should discuss any use of this product with their healthcare provider.
Purported Uses
To lower high cholesterol
A few clinical trials show that the use of red yeast rice can reduce cholesterol and triglyceride levels in the blood, but it is not certain whether these products are safe.
Patient Warnings
Citrinin, a toxic fermentation byproduct, has been found in a number of red yeast rice preparations.
Grapefruit juice may increase the effects of red yeast rice.
Side Effects
Stomach ache
Dizziness
Flatulence
Heartburn
Muscular disease resulting in muscle weakness
Case reports
Allergic reaction
Elevated liver enzymes
Liver injury, hepatitis
Unexpected high cholesterol
Skeletal muscle weakness and damage
Erectile dysfunction
Special Point
The U.S. Food and Drug Administration declared that the dietary supplement Cholestin, manufactured by Pharmanex, cannot be marketed as a dietary supplement because it contained lovastatin, a prescription drug.
Used in China as food and medicine for thousands of years, red yeast rice is the fermented product of the fungus, Monascus purpureus, grown on rice. It was first marketed as a dietary supplement in the United States by Pharmanex under the trade name Cholestin (1). The active constituent, monacolin K, is the same as lovastatin, an active ingredient in the cholesterol-lowering drug (2). A number of clinical trials have demonstrated effectiveness of red yeast rice preparations in reducing cholesterol levels in hyperlipidemic patients (3)(4)(5)(14)(15)(16)(17), but meta-analyses are mixed on whether it is safe (24)(25), with one citing a lack of regulation and standardized formulations. One of the extracts tested also did not lower blood pressure in hypertensive patients (20). In another study, co-supplementation with Coenzyme Q10 was found to be associated with improved LDL-cholesterolemia and endothelial reactivity in moderately hypercholesterolemic subjects (22).
It is important to note that several preparations of red rice yeast contain citrinin, a toxic fermentation byproduct (6).
Purported Uses
High cholesterol
Mechanism of Action
Components such as citrinin, monacolines and monankarin, and monascopyridines have been isolated from red yeast rice (10). Fermentation products are standardized to contain 0.4% 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors. HMG-CoA reductase is the rate-limiting enzyme in endogenous cholesterol biosynthesis (1). The principal HMG-CoA reductase inhibitor is monacolin K, also known as lovastatin (11).
Warnings
Citrinin, a toxic fermentation byproduct, was found at measurable concentrations in a number of preparations (6).
Grapefruit juice may increase the effects of red yeast rice (9).
Adverse Reactions
Stomach ache (3), heartburn, dizziness and flatulence (7), liver injury and myopathy (21)(23).
Hypertransaminasemia: In a 63-year-old woman following use of Equisterol, an over-the-counter lipid-lowering product containing guggulsterol and red yeast rice extract, for 6 months. Symptoms normalized after product was discontinued (18).
Severe hepatitis: In a 62-year-old woman after use of red yeast rice capsules for 4 months. Condition improved after product was discontinued (19).
Acute liver injury: In a 64-year-old woman not on medications, and 6 weeks after starting a red yeast rice supplement to decrease cholesterol (27).
Paradoxical hypercholesterolemia: On routine screening in a 23-year-old man, attributed to downregulation of cholesteryl ester transfer protein with the use of red yeast rice extract (28). Symptoms disappeared after product discontinuation.
Rhabdomyolysis: In a 28-year-old renal transplant recipient (12).
Myasthenia gravis: Associated with use of red yeast rice supplements (29).
Erectile dysfunction: In a 39-year-old male patient who used red yeast rice for 3 weeks as self-therapy to lower blood fats. Symptoms disappeared about 5 weeks after product discontinuation (26).
Dosage (OneMSK Only)
References
Schulz V, Hansel R, Tyler VE. Rational Phytotherapy: A Physician’s Guide to Herbal Medicine. New York: Springer, 2001.
FDA Talk Paper. FDA determines Cholestin to be an unapproved drug. T98-28. May 20, 1998.
Wang J, et al. Multicenter clinical trial of the serum lipid-lowering effects of a Monascus purpureus (red yeast) rice preparation from traditional Chinese medicine. Curr Ther Res Clin Exp. 1997 58(12):964-978.
