Red yeast rice
Synonyms and keywords: Red fermented rice; red kojic rice; red koji rice; ang-kak; beni-koji (Japan); akakoji (Japan); ang-chau (Taiwan)

# Overview
Red yeast rice (Chinese: , ; Taiwanese: ), is a bright reddish purple fermented rice, which acquires its color from being cultivated with the mold Monascus purpureus.  In China it is widely available under the brand name XueZhiKang (), and in Singapore it is available as HypocolTM.
Red yeast rice is sold in jars at Asian markets as a pasteurized wet aggregate, whole dried grains, or as a ground powder. It was a commonly used red food colouring in East Asian and Chinese cuisine prior to the discovery of chemical food colouring. It has also been used in Chinese herbal medicine.

# Production
Red yeast rice is produced by cultivating Monascus purpureus on polished rice. The rice is first soaked in water until the grains are fully saturated. The raw soaked rice can then either be directly inoculated, or steamed for the purpose of sterilizing and cooking the grains prior to inoculation. Inoculation is done by mixing M. purpureus spores or powdered red yeast rice together with the processed rice. The mix is then incubated in an environment around room temperature for 3-6 days. During this period of time, the rice should be fully cultured with M. purpureus, with each rice grain turning bright red in its core and reddish purple on the outside.
The fully cultured rice is then either sold as the dried grain, or cooked and pasteurized to be sold as a wet paste, or dried and pulverized to be sold as a fine powder. China is the world's largest producer of red yeast rice.
Due to the low cost of chemical dyes, some producers of red yeast rice have tried to adulterate their products with the red dye Sudan Red G.

## Active Compounds
Using high-performance liquid chromatography with photodiode array detector and tandem mass spectrometry, Li YG showed that a total of 14 monacolin compounds such as monacolin K (mevinolin), J, L, M, X, and their hydroxy acid form, as well as dehydromonacolin K, dihydromonacolin L, compactin, 3alpha-hydroxy-3,5-dihydromonacolin L, etc. were identified in red yeast rice. The constituent monacolin K, also known as lovastatin, is an inhibitor of the hydroxymethylglutaryl-CoA (HMG-CoA) reductase. Monacolins have been proved to be responsible for the cholesterol lowering effects of Monascus purpureus-fermented rice (red yeast rice).

# Uses

## Culinary
The dried grain can be prepared and eaten in the same manner as white rice--a common practice among Asians.  It can also be added to other foods.
Red yeast rice is used to color a wide variety of food products, including pickled tofu, red rice vinegar, Peking Duck, and Chinese pastries that require red food coloring. It is also traditionally used in the production of several types of Chinese wine, Japanese sake (akaisake), and Korean rice wine (hongju), imparting a reddish color to these wines.
Although used mainly for its colour in cuisine, red yeast rice imparts a subtle but pleasant taste to food.

## Chinese Medicine
In addition to its culinary use, red yeast rice is also used in traditional Chinese herbology and traditional Chinese medicine. Its use has been documented as far back as the Tang Dynasty in China in 800 A.D. and taken internally to invigorate the body, aid in digestion, and remove blood blockages.

## Western Medicine
Red yeast is used for maintaining desirable cholesterol levels in healthy people, reducing cholesterol in people with high cholesterol, for indigestion, diarrhea, improving blood circulation, and for spleen and stomach health. The active ingredient in red yeast is the same as the active ingredient in prescription drugs called statins used for high cholesterol. Thats why red yeast has all the possible side effects, drug interactions, and precautions associated with this type of drug. The American Heart Association warns against using red yeast until the results of long-term studies are in.
Red yeast rice when produced using the 'Went' strain of Monascus purpureus contains significant quantites of the HMG-CoA reductase inhibitor lovastatin which is also known as 'mevinolin', a naturally-occurring statin. It is sold as an over the counter dietary supplement for controlling cholesterol. There is strong scientific evidence for its effect in lowering blood levels of total cholesterol, low-density lipoprotein (LDL) ("bad cholesterol"), and triglyceride (TG) levels. Because an approved drug is identical to the molecule, it is therefore regulated as a drug by the Food and Drug Administration (FDA).
In 1998, the U.S. district court in Utah allowed a product containing red yeast rice extract known as CholestinTM to be sold without restriction, but this was reversed on appeal. CholestinTM as a product continues to be marketed but no longer contains red yeast rice (RYR).  Other companies sell red yeast rice products but most of them use a different strain of yeast or different growing conditions, resulting in RYR with a negligible statin content.  The labeling on these new products often says nothing about cholesterol lowering.  As late as August 2007, FDA noted supplements being sold containing significant lovastatin levels.

# Side Effects
- Rhabdomyolysis and depletion of Co-enzyme Q 10
- Myopathy
- Central nervous system defects can occur in the fetus if used by pregnant women during first trimester, as red yeast rice contains low doses of lovastatin.
- Rare side effects include:
Serious allergic reactions
Stomach discomfort
Heartburn
Dizziness
Citrin, which is a by-product of incomplete fermentation, can cause kidney damage.
- Serious allergic reactions
- Stomach discomfort
- Heartburn
- Dizziness
- Citrin, which is a by-product of incomplete fermentation, can cause kidney damage.

# Interactions
- Red yeast contains lovastatin, which might cause liver damage in some people. Therefore alcoholics must be warned against the possible adverse effects while taking red yeast rice. Similar caution must be maintained in patients taking acetaminophen (Tylenol), amiodarone (Cordarone), carbamazepine (Tegretol), isoniazid (INH), methotrexate (Rheumatrex), methyldopa (Aldomet), fluconazole (Diflucan), itraconazole (Sporanox), erythromycin (Erythrocin, Ilosone, others), phenytoin (Dilantin), lovastatin (Mevacor), pravastatin (Pravachol), simvastatin (Zocor), and many others.
- Myopathy is a possible side-effect of red yeast rice and drugs that cause muscle damage (cyclosporine, gemfibrozil, statins) interact with it and cause additional damage.
- Other drugs with possible interactions with red yeast rice include azole antifungals (ketoconazole), anticoagulants (warfarin), delavirdine, macrolide antibiotics (such as erythromycin,clarithromycin), nefazodone, HIV protease inhibitors (such as ritonavir, amprenavir), telithromycin.
- Grape fruit increases the levels of red yeast in the body by reducing its rate of metabolism and thereby increases its effects and side effects.
- St John's wort can reduce the levels of lovastatin in red yeast rice.

# Supportive Trial Data
- In 2006 Liu et al published a meta-analysis of clinical trials. The article cited 93 published, controlled clinical trials (91 published in Chinese). Total cholesterol decreased by 35 mg/dl, LDL-cholesterol by 28 mg/dl, triglycerides by 35 mg/dl, and HDL-cholesterol increased by 6 mg/dl.
- Zhao et al reported on a four-year trial in people with diabetes. There was a 40-50% reduction in cardiovascular events and deaths in the treated group.
- Ye et al reported on a four-year trial in elderly Chinese patients with heart disease. Deaths were down 32%. There is at least one report in the literature of a statin-like myopathy caused by red yeast rice.
- A randomized, double-blinded, placebo-controlled trial was conducted in 62 patients to assess the effectiveness and tolerability of red yeast rice (RYR) and therapeutic lifestyle change to treat dyslipidemic patients who are in-tolerant to statin therapy. All the patients were randomly assigned to treatment with either RYR or placebo twice daily for 24 weeks. All the patients were enrolled in a 12 week therapeutic lifestyle change program. In the RYR group LDL-C reduced by 43 mg/dL from baseline at week 12 and by 35 mg/dL at week 24 compared with a reduction of 11 mg/dL at week 12 and by 15 mg/dL at week 24 in the placebo group.
- A multicentered trial was conducted in nearly 5000 Chinese patients, who experienced a previous myocardial infarction, to assess the efficacy of Xuezhikang (XZK), a partially purified extract of red yeast rice, on lipoprotein and CV end points. All the patients were randomly assigned to treatment with either placebo or Xuezhikang for a mean follow-up period of 4.5 years. Results showed a 30% reduction in cardiovascular mortality and 33% in all-cause mortality. Long-term therapy with XZK significantly decreased the recurrence of coronary events and the occurrence of new CV events and deaths, improved lipoprotein regulation, and was safe and well tolerated.
- A multicentered, randomized, single-masked clinical trial enrolling 446 patients with hyperlipidemia was conducted in China to assess the efficacy of Cholestin3TM, a natural product of Monascus purpureus (red yeast) rice preparation. All the patients were randomly assigned to receive either a M purpureus (red yeast) rice preparation, or another Chinese herbal medicine, Jiaogulan (Gynostemma pentaphylla). At the end of 8 weeks, serum total cholesterol decreased significantly by 22.7% and LDL-cholesterol by 30.9% in the patients treated with a M purpureus rice preparation versus 7.0% and 8.3% reductions, respectively in the control group. M purpureus (red yeast) rice preparation also significantly elevated HDL-C levels by 19.9% versus an 8.4% rise in the control group.
- Heber D et al reported that red yeast rice significantly reduces total cholesterol, LDL cholesterol, and total triacylglycerol concentrations compared with placebo. In a double-blinded, placebo-controlled, prospectively randomized study enrolling 83 healthy subjects (46 men and 37 women aged 34-78 y) with hyperlipidemia who were not being treated with lipid-lowering drugs, it was shown that total cholesterol and LDL-C reduced significantly in the group treated with red yeast compared to the placebo group. 
- Combined results from a meta-analysis of 93 randomized controlled trials on three different RYR preparations showed significant reduction in total cholesterol, triglycerides and LDL-C levels and increase in HDL-C levels compared with placebo.
Although randomized controlled trials have shown that red yeast rice significantly decreases the recurrence of coronary events and the occurrence of new CV events and deaths, larger-scale clinical trials on safety and efficacy are necessary to confirm this finding.

# Conclusion
Despite its demonstrated efficacy in controlled clinical trials, red yeast rice is not recommended for patients with hypercholesterolemia due to:
- Lack of uniformity among products
- Possibility of contamination
- Risk of severe adverse reactions