A prospective study of dairy intake and the risk of type 2 diabetes in women.

OBJECTIVE: Although studies have indicated that increased dairy intake may reduce risk of overweight and insulin resistance syndrome, data directly relating dairy intake to type 2 diabetes remain sparse. RESEARCH DESIGN AND METHODS: We prospectively examined the associations between intake of dairy foods and calcium and incident type 2 diabetes in 37,183 women without a history of diabetes, cardiovascular disease, and/or cancer at baseline.
RESULTS: During an average of 10 years of follow-up, we documented 1,603 incident cases. After adjusting for potential confounders including BMI, smoking status, physical activity, family history of diabetes, alcohol consumption, history of hypertension, use of hormones, and high cholesterol, the relative risk for type 2 diabetes among women in the highest quintile of dairy intake was 0.79 (95% CI 0.67-0.94; P for trend = 0.007) compared with those in the lowest quintile. Each serving-per-day increase in dairy intake was associated with a 4% lower risk (0.96 [0.93-1.01]). The inverse association with type 2 diabetes appeared to be mainly attributed to low-fat dairy intake; the multivariate relative risks comparing the highest to the lowest quintiles was 0.79 (0.67-0.93; P for trend = 0.002) for low-fat dairy. The inverse relation between dairy intake and incident type 2 diabetes remained unchanged after further adjustment for dietary calcium, vitamin D, glycemic load, fat, fiber, and magnesium intake. These associations also did not vary significantly according to BMI.
CONCLUSIONS: A dietary pattern that incorporates higher low-fat dairy products may lower the risk of type 2 diabetes in middle-aged or older women.