A new study provides preliminary evidence that an herbal medicine used to help women cope with menopausal symptoms may reduce breast cancer risk.
However, much more research is needed before the herb, black cohosh, can be recommended to prevent the disease, Dr. Timothy R. Rebbeck of the University of Pennsylvania School of Medicine in Philadelphia and colleagues caution.
Many women use hormone-related supplements such as black cohosh, dong quai, red clover, ginseng and yam to deal with hot flashes and other symptoms of menopause, Rebbeck and his team note in the International Journal of Cancer.
To examine how the use of these herbs might relate to breast cancer risk, the researchers compared 949 women with breast cancer to 1,524 healthy controls.
African-American women were more somewhat likely than European Americans to use the herbs. Women who reported taking black cohosh (5 percent of blacks and 2 percent of whites) were at 61 percent lower risk of breast cancer, the researchers found.
Also, those who took an herbal preparation derived from black cohosh called Remifemin had a 53 percent lower risk of the disease.
Previous studies have shown that black cohosh can block cell growth, Rebbeck and colleagues note. The herb is also an antioxidant, and has been shown to have anti-estrogen effects as well. On the negative side, the herb can have side effects, and animal studies have suggested it may affect breast cancer severity.
“Substantial additional research must be undertaken before it can be established that black cohosh, or some compound found in black cohosh, is a breast cancer chemopreventive agent,” the researchers write.
“Furthermore,” they stress, “women may wish to seek guidance from their physician before using these compounds.”