Many people may have heard of red yeast rice, and quite a few have seen or even consumed products related to red yeast rice. However, most people probably don’t know where it comes from. Red yeast rice is created by inoculating rice that has been steamed with red yeast fungus and undergoing controlled fermentation conditions such as temperature and humidity.
What is Red Yeast Rice?
Many people might have heard of red yeast rice, and quite a few have seen or even consumed products related to red yeast rice. However, most individuals might not understand its origins. Red yeast rice is produced by inoculating red yeast onto steamed rice, followed by controlled fermentation conditions involving temperature, humidity, and other factors.
The process of making red yeast rice can be summarized as follows:
Red Yeast + Steamed Rice → Fermentation Processing → Red Yeast Rice → Grinding → Red Yeast Powder
In this process, the red yeast fungus grows and produces pigments, imparting a red color to the rice grains. The final step involves drying the red yeast rice to obtain the familiar product known as red yeast rice. Once red yeast rice is ground into a powder, it becomes the raw material for various health-related products.
Since red yeast rice is obtained through the fermentation of red yeast, it’s important to understand the classification of red yeast fungi. Red yeast fungi belong to the fungal kingdom (Fungi), class ascomycetes (Ascomycota), order eurotiales (Eurotiales), family monascaceae (Monascaceae), and genus monascus (Monascus). The genus monascus is a significant source of natural food colorants, widely used in various food applications such as wine, vinegar, and meat products. The two most common species within this genus are Monascus purpureus and Monascus anka.
What are the Nutritional Components of Red Yeast Rice?
Given that red yeast rice is a product of steamed rice combined with red yeast fermentation, its nutritional composition includes starch accounting for up to 70% of the weight, protein at 6%, minerals at 4%, fatty acids at 2%, and water content, among others. Additionally, it contains secondary metabolites produced during the fermentation process, such as pigments and organic acids. Among these secondary metabolites, one of the most extensively studied is Monacolin K, also known as lovastatin [1]. This component was first discovered by Japanese researchers and isolated from fermented foods produced by red yeast. Its concentration ranges from 0.3% to 0.4%, and it serves as a primary bioactive compound within red yeast rice [2]. The content of Monacolin K can vary depending on the species of red yeast used in fermentation.
What are the recommended proven effects and benefits of red yeast rice?
Traditionally, red yeast rice has often been used as an additive in food processing to achieve changes in flavor, color, and other aspects. Subsequent research led to the isolation of Monacolin K from red yeast rice, and its structure was identified to be similar to statins, a class of cholesterol-lowering drugs, particularly lovastatin (as seen in the figure below).
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| Lovastatin | Monacolin K |
1. Reducing Total Cholesterol and Low-Density Lipoprotein Cholesterol (LDL-c)
In a three-month test, daily administration of low-dose Monacolin K and folic acid to patients with hypercholesterolemia showed effective reduction in total cholesterol, LDL-c, and homocysteine levels, contributing to a decreased incidence of cardiovascular-related diseases[3].
💡 A large data analysis study indicated that the use of red yeast rice significantly reduced LDL-c compared to the placebo group, and its ability to lower LDL-c was comparable to statin medications commonly used for lipid lowering[4].
2. Cardiovascular Protection
In a six-month clinical trial, red yeast rice combined with coenzyme Q10 was administered to patients with mild hypercholesterolemia. The results demonstrated that this combination effectively lowered LDL-c, improved endothelial function, and enhanced arterial stiffness, showing positive cardiovascular protective effects[5].
Another study involved daily administration of Monacolin K combined with antioxidants (including green tea powder extract, coenzyme Q10, astaxanthin, resveratrol, and quercetin) to patients with mild hypercholesterolemia. This combination effectively lowered total cholesterol, LDL-c, and hs-CRP (a factor in cardiovascular disease), while also improving endothelial function[6].
3. Blood Pressure Reduction
Two retrospective articles have indicated that red yeast rice not only reduces LDL-c but also lowers systolic blood pressure, suggesting its potential for blood pressure reduction[7][8].
4. Improving Osteoporosis Symptoms
Animal and cell experiments have shown that red yeast rice supplementation may increase bone density, reduce bone resorption, and promote osteoblast proliferation, potentially delaying the symptoms of osteoporosis[9][10].
5. Anti-Cancer Properties
Numerous animal and cell experiments have suggested that red yeast rice can reduce tumor volume and decrease specific tumor markers[11]. Red yeast rice extract may contain active compounds that inhibit telomerase activity, promoting cancer cell apoptosis and demonstrating potential anti-cancer effects[12].
Does red yeast rice have any side effects?
In general, supplementing with red yeast rice to improve cardiovascular health is considered safe. However, there are three principles to follow when supplementing with red yeast rice to avoid potential side effects:
1. Avoid Concurrent Use with Cholesterol-Lowering Drugs
Reported side effects of red yeast rice primarily involve gastrointestinal issues such as stomach pain and bloating[13]. Supplementation within the recommended upper limit by health authorities is generally safe[14]. However, due to the structural similarity between Monacolin K (found in red yeast rice) and cholesterol-lowering mechanisms of statin medications, it is not recommended to simultaneously take red yeast rice supplements if you are already taking statins.
2. Beware of Citrinin Residue
Additionally, red yeast rice should be consumed with awareness of citrinin, a mycotoxin present in certain strains of red yeast rice. Citrinin is known to have toxic effects on the liver, kidneys, and potentially cause birth defects. It interferes with mitochondrial energy synthesis and lactate production within cells, leading to cellular damage[15][16]. When selecting red yeast rice products, it is advisable to choose those that do not contain citrinin or have citrinin levels below the regulated limit (< 2ppm).
3. Supplement with Coenzyme Q10 (CoQ10)
Coenzyme Q10 is an essential nutrient involved in energy metabolism within mitochondria and serves as a crucial antioxidant in the body. While the body can synthesize CoQ10, deficiencies can lead to conditions such as diabetes, neurodegenerative disorders, cancer, myalgia, heart failure, and cardiovascular diseases[17]. However, when supplementing with red yeast rice (containing Monacolin K or other red yeast metabolites), the same pathway that produces Monacolin K also inhibits the synthesis of CoQ10, thereby reducing its levels in the body[18]. Therefore, when taking red yeast rice products, it’s recommended to concurrently supplement with CoQ10.
When and How to Take Red Yeast Rice? (What Dosage is Effective?)
Firstly, it’s important to confirm the content of Monacolin K (also known as red yeast rice extract) in the product. No matter how much you consume, if the Monacolin K content is too low, it won’t be effective. So, how much should you take daily to achieve the cholesterol-lowering effects? A daily dosage of 13-15mg is considered ideal. Lastly, it’s recommended to take red yeast rice supplements during the time period after dinner and before sleep, as this is when the benefits are maximized.
In conclusion, for individuals dealing with cholesterol concerns, besides adopting proper dietary habits and regular exercise, it’s also advisable to consider choosing red yeast rice products in a timely, appropriate, and correct manner. This approach can help achieve proactive cholesterol management.
Further Reading: [2023] Comparison of 6 Commercial Red Yeast Rice Products, 4 Key Points to Consider When Choosing.
