The Lipid Lowering Effect of Red Yeast Rice
Red yeast rice has been popular these days and it isn’t foreign to see them on pharmacy shelves. As one of the top natural remedies for high cholesterol levels, red yeast rice is one of those few natural supplements that contain active ingredients that is identical to those found in prescription medications.
Red yeast rice is offered as a dietary supplement, alone or in combination with a balanced diet, to patients with dyslipidemia. Not separate from the rice variety, red yeast rice is produced by the fermentation of ordinary rice with a certain mold fungus of the Monascus genes. During fermentation, red dyes and various other potentially pharmacologically and toxicologically active ingredients are produced, including monacolin K which is identical to the statin drug lovastatin. The content of monacolin K can be varied in various red yeast rice extracts from different habitats. The concentration of monacolin K in red yeast rice products can be increased by optimizing the fermentation conditions and selection of the rice variety (1). Citrinin, a polyketide secondary metabolite found in food and feed that is produced by several fungi, including M. purpureus – can cause kidney damage as well as disrupt metabolic processes in the liver. Thus it is essential to ensure the red yeast rice product is free from citrinin, as up to 80% of red yeast rice products are were found to contain this mycotoxin (2).
For patients with hypercholesterolemia that are not qualified for treatment with statin drugs based on their cardiovascular risk, nutraceuticals like red yeast rice products can be available without prescription, and thus seen by some a possible further preventive measure that can decrease LDL levels.
Monacolin K, which is found to be structurally identical to lovastatin, has its primary mechanism of action in inhibiting 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase, the rate-controlling enzyme of the cholesterol synthesis pathway. The lipid lowering properties of red yeast rice appear to be multifactorial. Besides inhibiting HMG-CoA, recent animal data in hamsters suggested that red yeast rice could increase the hepatic excretion of bile acids, thus increasing the availability of intrahepatic cholesterol to be used for the bile synthesis, hence decreasing the plasma cholesterol levels and reduce the risk associated with the formation of atherosclerotic lesions (3).
Mechanism of action of Red Yeast Rice (Adapted from Patel 2016)
The safety of red yeast rice alone or in combined nutraceuticals has been investigated in clinical trials, which the amount as low as 3 mg/day till the high dose of 10mg/day of monacolin K were found to be well tolerated by patients with dyslipidemia, with few or no adverse events (4).
Besides lowering cholesterol, red yeast rice also been reported to have other potential benefits, such as improve heart health. High cholesterol as one of the main risk factors of heart disease can cause arteries to narrow and stiffen, leading to increased risk of heart attack and stroke. Red yeast rice does not only effective in reducing levels of total and LDL cholesterol, as well as triglycerides and blood pressure, it also helps improve endothelial function, maintaining the vascular and heart health (5). One study has reported that red yeast rice was able to reduce blood sugar, insulin levels, systolic blood pressure in people with metabolic syndrome. Red yeast rice could also reduce levels of oxidative stress, that could lead to chronic inflammation, when combine with olive extract within 8 weeks, by up to 20 percent (6).
Red yeast rice is widely used in prescriptions, as well as an alternative medicine and a food supplement, in Asia, the United States and European countries. Number of studies have supported the traditional use of red yeast rice as lowering cholesterol approach. Adding red yeast rice extract to your diet can help lower your cholesterol levels, which reduces the risk of cardiovascular disease.
Huang, H. N., Hua, Y. Y., Bao, G. R., Xie, L. H. (2006). The quantification of monacolin K in some red yeast rice from Fujian province and the comparison of the other product. Chem. Pharm. Bull. 54 (5), 687–689. doi: 10.1248/cpb.54.687
Klimek M, Wang S, Ogunkanmi A. Safety and efficacy of red yeast rice (Monascus purpureus) as an alternative therapy for hyperlipidemia. P T. 2009 Jun;34(6):313-27. PMID: 19572049; PMCID: PMC2697909.
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Mazza A , Schiavon L , Rigatelli G , Torin G , Montanaro F , Lenti S . The short-term supplementation of monacolin K improves the lipid and metabolic patterns of hypertensive and hypercholesterolemic subjects at low cardiovascular risk. Food Funct. 2018 Jul 17;9(7):3845-3852. doi: 10.1039/c8fo00415c. PMID: 29951651.
Xiong X, Wang P, Li X, Zhang Y, Li S. The effects of red yeast rice dietary supplement on blood pressure, lipid profile, and C-reactive protein in hypertension: A systematic review. Crit Rev Food Sci Nutr. 2017 Jun 13;57(9):1831-1851. doi: 10.1080/10408398.2015.1018987. PMID: 26167669.
Hermans N, Van der Auwera A, Breynaert A, Verlaet A, De Bruyne T, Van Gaal L, Pieters L, Verhoeven V. A red yeast rice-olive extract supplement reduces biomarkers of oxidative stress, OxLDL and Lp-PLA2, in subjects with metabolic syndrome: a randomised, double-blind, placebo-controlled trial. Trials. 2017 Jul 3;18(1):302. doi: 10.1186/s13063-017-2058-5. PMID: 28673363; PMCID: PMC5496259.
Patel S. Functional food red yeast rice (RYR) for metabolic syndrome amelioration: a review on pros and cons. World J Microbiol Biotechnol. 2016 May;32(5):87. doi: 10.1007/s11274-016-2035-2. Epub 2016 Apr 2. PMID: 27038957.