Is red meat intake a risk factor for breast cancer among premenopausal women?

Breast cancer is the second leading cause of cancer deaths in women today and is the most common cancer among women. Although a number of risk factors such as genetics, family history, parity, age at first birth, and age at menarche and menopause have been established, most are difficult to modify. Diet, however, is a potentially modifiable approach for prevention and a variety of dietary patterns have been examined with respect to their role in breast cancer. One such dietary factor is red meat consumption. Red meat intake has been hypothesized to increase breast cancer risk but while both case-control and ecologic studies have supported a positive association, prospective cohort studies have been inconsistent. One explanation for this inconsistency may be related to menopausal status. We performed a meta-analysis on the association between breast cancer risk and red meat consumption in premenopausal women. A total of ten studies were identified. The summary relative risk was 1.24 (95% CI 1.08-1.42). Case-control studies (N = 7) had a risk of 1.57 (95% CI 1.23-1.99), while cohort studies (N = 3) had a summary relative risk of 1.11 (95% CI 0.94-1.31).