In the study reviewed here, women who took black cohosh to reduce their menopausal symptoms were about 60% less likely to develop breast cancer than women who didn't take black cohosh. Does this mean black cohosh lowers breast cancer risk? Maybe. But this study all by itself DOESN'T answer that question.
This small study does show that taking black cohosh was ASSOCIATED with a decrease in breast cancer risk. This isn't the same thing as concluding that black cohosh caused the decrease in risk. As the researchers point out, much more research needs to be done to prove conclusively that black cohosh lowers breast cancer risk.
Black cohosh seems to help decrease menopausal symptoms because it contains phytoestrogens, substances that act a lot like estrogen. When you go through menopause, your estrogen levels drop significantly. This is why many women experience hot flashes. Herbal remedies such as black cohosh that contain phytoestrogens are thought to help because the phytoestrogens take the place of the missing estrogen. Phytoestrogens also can have anti-estrogen effects. Since estrogens can cause hormone-receptor-positive breast cancer to develop and grow, it's possible that the anti-estrogen effects of black cohosh explain the reduced risk in the women who used it.
Very little research has been done on the effectiveness and safety of black cohosh or other supplements to treat hot flashes. Until doctors know more, we can't recommend black cohosh to lower breast cancer risk. If you're considering taking black cohosh or any other herbal supplement for menopausal symptoms, talk to your doctor before taking the supplement. Some dietary supplements can interfere with breast cancer treatment and prescription medications. To learn more about supplements, visit the breastcancer.org Nutrition Section. To learn more about risk reduction, visit the breastcancer.org Lower Your Risk Section.
NEW YORK (Reuters Health) - 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."
SOURCE: International Journal of Cancer, April 1, 2007.
Breastcancer.org 7 East Lancaster Avenue, 3rd Floor Ardmore, PA 19003
Learn more about our commitment to your privacy
© 2009 Breastcancer.org - All rights reserved.
Breastcancer.org is a non-profit organization dedicated to providing information and community to those touched by this disease. Learn more about our commitment to providing complete, accurate, and private breast cancer information.
