Objective: The aim of this study was to prospectively assess the relation between red meat intake and incidence of type 2 diabetes.
Research design and methods: Over an average of 8.8 years, we evaluated 37,309 participants in the Women's Health Study aged >/=45 years who were free of cardiovascular disease, cancer, and type 2 diabetes and completed validated semiquantitative food frequency questionnaires in 1993.
Results: During 326,876 person-years of follow-up, we documented 1,558 incident cases of type 2 diabetes. After adjusting for age, BMI, total energy intake, exercise, alcohol intake, cigarette smoking, and family history of diabetes, we found positive associations between intakes of red meat and processed meat and risk of type 2 diabetes. Comparing women in the highest quintile with those in the lowest quintile, the multivariate-adjusted relative risks (RRs) of type 2 diabetes were 1.28 for red meat (95% CI 1.07-1.53, P < 0.001 for trend) and 1.23 for processed meat intake (1.05-1.45, P = 0.001 for trend). Furthermore, the significantly increased diabetes risk appeared to be most pronounced for frequent consumption of total processed meat (RR 1.43, 95% CI 1.17-1.75 for >/=5/week vs. <1/month, P < 0.001 for trend) and two major subtypes, which were bacon (1.21, 1.06-1.39 for >/=2/week vs. <1/week, P = 0.004 for trend) and hot dogs (1.28, 1.09-1.50 for >/=2/week vs. <1/week, P = 0.003 for trend). These results remained significant after further adjustment for intakes of dietary fiber, magnesium, glycemic load, and total fat. Intakes of total cholesterol, animal protein, and heme iron were also significantly associated with a higher risk of type 2 diabetes.
Conclusions: Our data indicate that higher consumption of total red meat, especially various processed meats, may increase risk of developing type 2 diabetes in women.