An analysis of nine proprietary Chinese red yeast rice dietary supplements: implications of variability in chemical profile and contents

Abstract

Objectives: Some strains of Chinese red yeast rice, when prepared by solid fermentation, produce compounds called monacolins that inhibit cholesterol production. When used as a dietary supplement to achieve and maintain healthy cholesterol levels, Chinese red yeast rice has significant potential to reduce health care costs and contribute to public health by reducing heart disease risk in individuals with moderate elevations of circulating cholesterol levels. Whereas one proprietary strain of Chinese red yeast rice has been demonstrated to lower cholesterol levels significantly in clinical trials, other strains being sold as Chinese red yeast rice dietary supplements have not undergone similar evaluation. In order to determine whether the results of a clinical trial conducted with one strain of Chinese red yeast rice could be generalized to other preparations of Chinese red yeast rice, nine different commercially available dietary supplements were purchased tested for chemical constituents.

Design: Monacolins were measured by high performance liquid chromatography (HPLC) that separates the various monacolins in Chinese red yeast rice. Citrinin concentration, a toxic fermentation byproduct, was measured by radioimmunoassay.

Results: Total monacolin content varied from 0% to 0.58% w/w and only 1 of 9 preparations had the full complement of 10 monacolin compounds. Citrinin was found at measurable concentrations in 7 of the 9 preparations.

Conclusions: The findings from clinical trials demonstrating significant and clinically relevant cholesterol reduction using a defined Chinese red yeast rice preparation containing 10 different monacolins cannot be generalized to preparations that do not contain the same levels and profile of monacolins. Standardized manufacturing practices should be established for Chinese red yeast rice sold as a dietary supplement in order ensure equivalence of content of active ingredients in preparations being sold to the public and to limit the production of unwanted byproducts of fermentation such as citrinin. In common with other botanical dietary supplements, the full potential of this product will not be realized until standards for production and labeling of Chinese red yeast rice are further developed.