Black Cohosh May Prevent Breast Cancer

Healthnotes Newswire (June 21, 2007)—Women who take the herb black cohosh (Cimicifuga racemosa) are less likely to get breast cancer, according to new research published in the International Journal of Cancer.

“With the serious health concerns that have been raised about the use of estrogen and progestin-containing hormone replacement therapy in recent years, many women have turned to complementary-alternative medicines to alleviate symptoms of menopause,” said Timothy R. Rebbeck, PhD, professor of Epidemiology in the Department of Biostatistics and Epidemiology at the University of Pennsylvania and lead author of the new study. “The long-range effects of these compounds have not been studied. Ours is the first report that black cohosh confers a degree of protection from breast cancer, which represents a potentially important piece of information for women who take, or who might consider taking, these compounds.”

Many women use hormone-related supplements to manage their menopausal symptoms, which often contain phytoestrogens and other compounds that mimic the effect of the body’s own estrogens. The concentrations and composition of these compounds, which are mainly extracted from herbs, vary widely.

Black cohosh has a long tradition of use in both American and Chinese herbal medicine. In recent years, extracts of this herb have been shown to have beneficial effects on menopausal symptoms in some, but not all, randomized clinical trials. Unlike other phytoestrogens, black cohosh may have slight anti-estrogenic effects. It does not appear to bind to estrogen receptors and has been shown to prevent cellular DNA damage by acting as an antioxidant. These observations led researchers to believe that black cohosh use may be associated with protection from breast cancer.

Rebbeck and colleagues evaluated whether use of black cohosh–containing supplements was associated with breast cancer risk in a retrospective study in the Philadelphia metropolitan area. In all, 949 women with breast cancer and 1,524 women without breast cancer were evaluated.

Use of hormone-related supplements varied significantly by race, with black women being more likely than white women to use herbal preparations, including black cohosh, ginseng, and red clover. Women who had used black cohosh supplements (including the extract called Remifemin) were 47% less likely to have breast cancer at the time of the analysis.

Because the study’s design is preliminary and limits definitive conclusions, additional research is needed before it can be established that black cohosh, or some compound found in black cohosh, helps prevent breast cancer.

“Women may wish to seek guidance from their physician before using these compounds,” cautioned Dr. Rebbeck. “Our data do not suggest that use of black cohosh is an appropriate substitute for standard hormone replacement therapy.”

(Int J Cancer 2007;120:1523–28)

Jeremy Appleton, ND, CNS, is a licensed naturopathic physician, certified nutrition specialist, and published author. Dr. Appleton was the Nutrition Department Chair at the National College of Naturopathic Medicine, has served on the faculty at Bastyr University of Natural Health Sciences, and is a former Healthnotes Senior Science Editor and a founding contributor to Healthnotes Newswire. He has worked extensively in scientific and regulatory affairs in the supplement industry and is now a consultant through his company Praxis Natural Products Consulting and Wellness Services.

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