Changes in dairy product consumption and risk of type 2 diabetes: results from 3 large prospective cohorts of US men and women.

Background: Whether changes in dairy product consumption are related to subsequent risk of type 2 diabetes (T2D) remains unknown. Objective: We evaluated the association of long-term changes in dairy product consumption with subsequent risk of T2D among US men and women. Methods: We followed up 34,224 men in the Health Professionals Follow-Up Study (1986-2012), 76,531 women in the Nurses' Health Study (1986-2012), and 81,597 women in the Nurses' Health Study II (1991-2013). Changes in dairy consumption were calculated from consecutive quadrennial FFQs. Multivariable Cox proportional regression models were used to calculate HRs for T2D associated with changes in dairy product consumption. Results of the 3 cohorts were pooled using an inverse variance-weighted, fixed-effect meta-analysis. Results: During 2,783,210 person-years, we documented 11,906 incident T2D cases. After adjustment for initial and changes in diet and lifestyle covariates, decreasing total dairy intake by >1.0 serving/d over a 4-y period was associated with an 11% (95% CI: 3%, 19%) higher risk of T2D in the subsequent 4 y compared with maintaining a relatively stable consumption (i.e., change in intake of +/- 1.0 serving/wk). Increasing yogurt consumption by >0.5 serving/d was associated with an 11% (95% CI: 4%, 18%) lower T2D risk, whereas increasing cheese consumption by >0.5 serving/d was associated with a 9% (95% CI: 2%, 16%) higher risk compared with maintaining stable intakes. Substituting 1 serving/d of yogurt or reduced-fat milk for cheese was associated with a 16% (95% CI: 10%, 22%) or 12% (95% CI: 8%, 16%) lower T2D risk, respectively. Conclusions: Increasing yogurt consumption was associated with a moderately lower risk of T2D, whereas increasing cheese consumption was associated with a moderately higher risk among US men and women. Our study suggests that substituting yogurt or reduced-fat milk for cheese is associated with a lower risk of T2D.