A recent study in the Journal of Medicinal Food finds that red yeast rice can significantly slow the growth of prostate cancer cells. Rice that has been fermented with the red yeast, Monascus purpureus, contains compounds called monacolins, one of which – monacolin K – has the same chemical structure as the cholesterol-lowering drug, lovastatin (Mevacor). In fact, studies have shown that Chinese red yeast rice lowers cholesterol as well as lovastatin.
Because cholesterol is needed to produce the sex hormones that fuel the growth of certain cancers, researchers have been investigating whether statins, and similarly, red yeast rice might be effective cancer treatments. One study published last year found that red yeast rice triggered the death of colon cancer cells. The same team of researchers wanted to learn whether red yeast rice might have a similar effect on prostate cancer cells, and particularly on prostate cancer cells that are not dependent on male hormones to grow (androgen-independent prostate cancers).
The early stages of prostate cancer are typically androgen dependent—meaning that they need male hormones to grow. These early cancers are usually first treated with a type of hormone therapy that attempts to reduce or remove androgens. “However, after successful treatment, the emergence of androgen-independent prostate cancer is common,” says lead study author Mee Young Hong, PhD, an assistant professor at the School of Exercise and Nutritional Sciences at San Diego State University. “These androgen-independent prostate tumors are more difficult to treat, and they lead progressively to metastasis [cancer spread] and death.”
Dr. Hong and her colleagues compared the drug lovastatin to red yeast rice on both androgen-dependent and androgen-independent prostate cancer cells. The lovastatin decreased prostate cancer cell growth by 20 percent in the androgen-dependent cancer cells, and by 15 percent in the androgen-independent cells. The same dose of red yeast rice inhibited androgen-dependent prostate cancer cells by 47 percent, and androgen-independent cells by 62 percent. When treatment was extended for another day, red yeast rice inhibited prostate cancer cell growth even more – by 77 percent and 65 percent, respectively.
Even a form of red yeast rice that did not contain monacolin K reduced prostate cancer growth, suggesting that red yeast rice contains other components that are active against cancer cells. Among these components are red pigments, which are thought to have anti-cancer effects.
The authors say that by affecting cholesterol, red yeast rice can reduce androgen production in prostate cancer cells. This may not only halt cancer cell growth, but also help prevent early, androgen-dependent prostate cancers from progressing to the more advanced and harder-to-treat androgen-independent cancers. “Our current study proves that red yeast rice is protective against androgen-independent, as well as androgen-dependent prostate cancers,” Dr. Hong says. “Therefore, the use of red yeast rice would be a novel approach to treat advanced androgen-independent prostate cancer in order to reduce overall prostate cancer mortality.”
Right now this therapy is still experimental. Animal studies, and ultimately human trials need to be conducted before red yeast rice can be recommended as a cancer treatment.
In 1998, the U.S. Food and Drug Administration (FDA) pulled red yeast rice supplements from the market because they contain an ingredient that is identical to an approved drug (statin), and because they can cause side effects similar to those of statins (muscle weakness and liver damage). You can still buy red yeast rice supplements in your local health food store; however, these supplements are produced using a different strain of yeast or fermentation process than those used in this study. Before using any dietary supplement, talk to your doctor to make sure that it is safe and appropriate.
Hong MY, Seeram NP, Zhang Y, Heber D. Chinese red yeast rice versus lovastatin effects on prostate cancer cells with and without androgen receptor overexpression. Journal of Medicinal Food. 2008;11:657-666.
Hong, Mee Young, et al. Anticancer effects of Chinese red yeast rice versus monacolin K alone on colon cancer cells. Journal of Nutritional Biochemistry. 2008:19:448-458
Graaf MR, et al. The risk of cancer in users of statins. Journal of Clinical Oncology, 2004. 22;2388-2394.