Prostate cancer, one of the most common types of cancer in men, is usually slow-growing. Your doctor might decide to postpone treatment. However, some aggressive types of fast-growing prostate cancer require treatment with medication and radiation therapy. Although herbalists recommend red clover to help combat prostate cancer, red clover extract contains estrogen-like compounds that might cause certain types of cancer cells to proliferate. Most experts advise that men with prostate cancer avoid red clover.
Features
Red clover, a perennial herb that grows wild in meadows throughout North America, is dried and used in herbal remedies. Red clover has traditionally been used to treat inflammatory skin disorders such as eczema, as well as cancer, whooping cough, jaundice, asthma and mastitis. It has also been employed for its detoxifying and expectorant effects. Red clover contains isoflavones, or plant-based chemicals, that produce estrogen-like effects in the body; the most active are biochinin A, formononetin, genistein and daidzein. Red clover also contains saponins, salicylic acid, assorted minerals and vitamins, and coumaric acid, a natural blood thinner.
Effects and Expert Recommendations
Drugs.com reports that red clover is being investigated for its potential use as a treatment for prostate and endometrial cancer, and adds that one of red clover's isoflavones has chemoprotective effects. However, the website points out that red clover's isoflavones act as estrogen agonists, increasing the proliferation of breast cancer cells. Memorial Sloan-Kettering Cancer Center concurs that biochinin A in red clover confers a protective effect against cancer, but notes that red clover increased resistance of prostate cancer cells to high-dose radiation in one test tube study. MSKCC advises that patients with hormone-sensitive cancers -- such as prostate, breast, ovarian and endometrial cancers -- avoid red clover due to its estrogenic effects. Similarly, University of Maryland Medical Center does not endorse the use of red clover for preventing cancer, and advises patients with hormone-sensitive cancers not to use it.
Supporting Research
Some clinical and laboratory studies support beneficial effects of red clover extracts on prostate cancer. In a scientific review published in 2006 in "The Journal of the Association of Analytical Communities International," the authors evaluated the results of trials investigating the effects of isoflavones on serum prostate-specific antigen -- or PSA -- levels of prostate cancer patients. High PSA levels are associated with prostate cancer. In four out of eight trials, isoflavones favorably affected PSA levels, although researchers were unable to conclude by what mechanism. Describing the results as "encouraging," the authors called for further study on isoflavones for the treatment of prostate cancer.
Inconclusive and Opposing Research
In a randomized, placebo-controlled clinical trial published in 2007 in "Nutrition and Cancer," researchers found that 12 weeks of treatment with 80 mg of purified isoflavones failed to have any significant beneficial effect on men with early-stage localized prostate cancer. In a laboratory study published in 2010 in "International Journal of Radiation Oncology, Biology, Physics," researchers found that red clover extracts inhibited the growth rate of normal prostate cells.
References
- Drugs.com: Complete Red Clover Information
- Memorial Sloan-Kettering Cancer Center: Red Clover
- University of Maryland Medical Center; Red Clover; December 2008
- "The Journal of the Association of Analytical Communities International," An Overview of the Health Effects of Isoflavones with an Emphasis on Prostate Cancer Risk and Prostate-Specific Antigen Levels; M. Messina, et al.; August 2006
- "Nutrition and Cancer"; A Phase II Randomized, Placebo-Controlled Clinical Trial of Purified Isoflavones in Modulating Steroid Hormones in Men Diagnosed with Localized Prostate Cancer; N.B. Kumar, et al.; 2007
- "International Journal of Radiation Oncology, Biology, Physics"; Prostate-Specific Natural Health Products (Dietary Supplements) Radiosensitize Normal Prostate Cells; Y. Hasan, et al.; March 2010
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