A diet rich in red meat may be associated with a greater risk of certain forms of breast cancer in premenopausal women, researchers reported in a study released Monday.
The breast cancer type that seems to be linked to red meat consumption is called hormone receptor-positive breast cancer, which suggests estrogen or progesterone are involved in fueling tumor growth.
Red meat can contain hormones given to animals to enhance the quality of their meat.
Dr. Eunyoung Cho of Boston's Brigham and Women's Hospital studied 90,659 women who were part of the ongoing Nurses' Health Study II.
Nurses were followed from 1991 through 2003. Participants recorded how often they consumed more than 130 different foods and beverages. Cho found that 1,021 developed breast cancer. More than half of the cancers were hormone receptor-positive, which occurred predominantly among women who had consumed the most red meat.