For many women, taking the herbal extract black cohosh is an effective way to relieve menopausal symptoms. However, new research shows the supplement may not be safe for women with breast cancer or women who have undetected breast tumors.
Researchers from the Mylan School of Pharmacy at Duquesne University studied how the herbal treatment affected female mice. Results show black cohosh did not increase the incidence of new tumors but did increase the number of tumors that spread to the lungs. Researchers say the supplement may not increase or decrease a woman's risk of developing breast cancer, but it may encourage some breast tumors to metastasize.
Researchers also say black cohosh could affect women who have undetected breast tumors. Vicki Davis, Ph.D., from Mylan School of Pharmacy and the Graduate School of Pharmaceutical Sciences at Duquesne University, says, "Although it is unfortunate to be eliminating another option for women needing therapies to relieve menopausal symptoms, our findings suggest that women who may be at high risk of having an undetected breast tumor and certainly those who do have breast cancer should proceed with caution or simply avoid taking black cohosh until we learn if there are ways to circumvent these adverse effects."
Black cohosh is one of the most commonly used alternative supplements to treat hot flashes and other menopausal symptoms. The herb is native to North America and is extracted from a perennial plant.