Red Meat Intake May Raise Breast Cancer Risk

Analysis of data from more than 90,000 premenopausal women suggests greater intake of red meat may increase the risk of breast cancer, according to Harvard researchers. In their study, published in the Archives of Internal Medicine (166:2253-59, 2006), researchers from Boston's Brigham & Women's Hospital & Harvard University assessed red meat intake via a food frequency questionnaire in women aged 26 to 46 participating in the Nurses Health Study II. During 12 years of follow-up in the 90,659-strong cohort, 1,021 cases of invasive breast carcinoma were documented. Greater red meat intake was strongly related to estrogen- and progesterone-receptor positive (ER+/PR+) breast cancers, but not to the negative (ER-/PR-) cancers.

Compared to women who consumed three or fewer servings per week of red meat, there was a 14% increase in ER+/PR+ breast cancer in the three-five servings group, a 42% increase in those eating more than five servings a week but one or fewer per day, and a striking 97% increase among women eating more than 1.5 servings per day.

The study was the first to examine the relationship between red meat consumption and breast cancer in this younger cohort, as well as to break it out by type of breast cancer. While more research is needed to elucidate the reasons behind the findings, this may provide additional incentive for women to curb excessive red meat intake. Previous studies have suggested red meat may increase the risk for various cancers by increasing intake of carcinogenic compounds formed during the cooking process, or that naturally occurring substances may mimic hormonal activity.