Red yeast rice (Monascus purpureus)

 
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Red yeast rice
Red yeast rice

Background

Red yeast rice is the product of yeast ( Monascus  purpureus ) grown on rice, and is served as a dietary staple in some Asian countries. It contains several compounds collectively known as Monacolins, substances known to inhibit cholesterol synthesis. One of these, "Monacolin K" is a potent inhibitor of HMG-CoA reductase, and is also known as Mevinolin or Lovastatin (Mevacor®, a drug produced by Merck & Co., Inc).

 

Red yeast rice extract has been sold as a natural cholesterol-lowering agent in over the counter supplements, such as CholestinTM (Pharmanex, Inc). However, there has been legal and industrial dispute as to whether red yeast rice is a drug or dietary supplement, involving this manufacturer, the U.S. Food and Drug Administration (FDA) and the pharmaceutical industry (particularly producers of HMG-CoA reductase inhibitor prescription drugs or "statins").

 

The use of red yeast rice in China was first documented in the Tang Dynasty in 800 A.D. A detailed description of its manufacture is found in the ancient Chinese pharmacopoeia, Ben Cao Gang Mu-Dan Shi Bu Yi, published during the Ming Dynasty (1368-1644). In this text, red yeast rice is proposed to be a mild aid for gastric problems (indigestion, diarrhea), blood circulation and spleen and stomach health. Red yeast rice in a dried, powdered form is called Zhi Tai. When extracted with alcohol it is called Xue Zhi Kang.

 

Synonyms

Angkak, beni-koju, CholestinTM, hong qu, hung-chu,  Monascus , red koji, red leaven, red rice, red rice yeast, red yeast rice, Xue Zhi Kang, Zhi Tai.

 

Evidence

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Uses based on scientific evidence Grade*
High cholesterol

Since the 1970s, human studies have reported that red yeast lowers blood levels of total cholesterol, low-density lipoprotein/LDL ("bad cholesterol"), and triglyceride levels. Other products containing red yeast rice extract can still be purchased, mostly over the Internet. However, these products may not be standardized, and effects are not predictable. For lowering cholesterol, there is better evidence for using prescription drugs such as lovastatin.

A
Coronary heart disease

Preliminary evidence shows that taking Monascus purpureus by mouth may result in cardiovascular benefits and improve blood flow. Additional study is needed before a firm recommendation can be made.

C
Diabetes

Early human evidence suggests the potential for benefits in diabetics. Additional study is needed before a firm recommendation can be made.

C

 

*Key to grades
A: Strong scientific evidence for this use;
B: Good scientific evidence for this use;
C: Unclear scientific evidence for this use;
D: Fair scientific evidence against this use;
F: Strong scientific evidence against this use.

 

Grading rationale

Uses based on tradition or theory
The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Acetaminophen toxicity, anthrax, anti-inflammatory, antioxidant, artherosclerosis, blood circulation problems, bruised muscles, bruises, cancer, colic in children, cuts, diarrhea, dysentery (bloody diarrhea), exercise performance enhancement, food additive (coloring), food preservative, hangover, high blood pressure, HIV (associated hyperlipidemia), immunosuppression, indigestion, liver disorders, metabolic disorders, obesity, ovarian cancer, postpartum problems, spleen problems, stomach problems, weight loss, wounds.

Dosing

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Adults (18 years and older):
1,200 milligrams of concentrated red yeast powder capsules have been taken two times per day by mouth with food.

 

The average consumption of naturally occurring red yeast rice in Asia has been reported as 14-55 grams per day.

 

Children (younger than 18 years):
There is not enough scientific evidence to recommend red yeast for children.

 

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies
There is one report of anaphylaxis (a severe allergic reaction) in a butcher who touched meat containing red yeast.

 

Side Effects and Warnings
There is limited evidence about the side effects of red yeast. Mild headache and abdominal discomfort can occur. Side effects may be similar to those for the prescription drug lovastatin (Mevacor®). Heartburn, gas, bloating, muscle pain or damage, dizziness, asthma, and kidney problems are possible. People with liver disease should not use red yeast products.

 

In theory, red yeast may increase the risk of bleeding. Caution is advised in patients with bleeding disorders or taking drugs that may increase the risk of bleeding. Dosing adjustments may be necessary. A metabolite of  Monascus  called mycotoxin citrinin (CTN) in fermentation may be harmful.

 

Pregnancy and Breastfeeding
Prescription drugs with similar chemicals as red yeast cannot be used during pregnancy. Therefore, it is strongly recommended that pregnant or breast-feeding women not take red yeast.

 

Interactions

Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.

Interactions with Drugs
There are not many studies of the interactions of red yeast rice extract with drugs. However, because red yeast rice extract contains the same chemicals as the prescription drug lovastatin, the interactions may be the same. Fibrate drugs or other cholesterol -lowering medication may cause additive effects or side effects when taken with red yeast. Alcohol and other drugs that may be toxic to the liver should be avoided with red yeast rice extract. Taking cyclosporine, ranitidine (Zantac®) and certain antibiotics with red yeast rice extract may increase the risk of muscle breakdown or kidney damage.

 

Certain drugs may interfere with the way the body processes red yeast using the liver's "cytochrome P450" enzyme system. Inhibitors of cytochrome P450 may increase the chance of muscle and kidney damage if taken with red yeast.

 

In theory, red yeast may increase the risk of bleeding when taken with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants ("blood thinners") such as warfarin (Coumadin®) or heparin, anti-platelet drugs such as clopidogrel (Plavix®), and non-steroidal anti-inflammatory drugs such as ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®).

 

Red yeast may produce gamma-aminobutyric acid (GABA), and therefore can have additive effects when taken with drugs that affect GABA such as neurontin (Gabapentin®).

 

Red yeast may also interact with digoxin, niacin, thyroid medications and blood pressure lowering medications. Caution is advised.

 

Red yeast may alter blood sugar levels in the blood, and patients with diabetes or taking insulin or blood sugar lowering medications by mouth should consult with a qualified healthcare professional, including a pharmacist. Dosing adjustments may be necessary.

 

Interactions with Herbs and Dietary Supplements
Red yeast may interact with products that cause liver damage or are broken down in the liver. Grapefruit juice may increase the blood levels of red yeast. Milk thistle, St. John's wort, niacin and vitamin A may interact with red yeast rice extract. Coenzyme Q levels may be lowered by red yeast rice extract. Cholesterol-lowering herbs and supplements like guggul or fish oils may have increased effects when taken with red rice yeast. Although not well studied, red yeast may also interact with astaxanthin and zinc. Caution is advised.

 

Certain herbs and supplements may interfere with the way the body processes red yeast using the liver's "cytochrome P450" enzyme system. Inhibitors of cytochrome P450 may increase the chance of muscle and kidney damage if taken with red yeast.

 

In theory, red yeast may increase the risk of bleeding when taken with herbs and supplements that are believed to increase the risk of bleeding. Multiple cases of bleeding have been reported with the use of  Ginkgo biloba , and fewer cases with garlic and saw palmetto. Numerous other agents may theoretically increase the risk of bleeding, although this has not been proven in most cases.

 

Red yeast may also interact with digitalis (foxglove), or herbs and supplements that affect the thyroid or blood pressure. It may also have anti-inflammatory effects and should be used cautiously with other herbs or supplements that may have anti-inflammatory effects.

 

Red yeast may alter blood sugar levels in the blood, and patients with diabetes or taking herbs and supplement to control blood sugar should use with caution.