Dairy consumption and risk of type 2 diabetes mellitus: a meta-analysis of cohort studies

Background/Objectives: Milk intake is widely recommended for a healthy diet. Epidemiological studies have suggested that the consumption of dairy products may be associated with a reduction in type 2 diabetes mellitus (T2DM). A meta-analysis was conducted to elucidate the association between dairy products consumption and T2DM. Subjects/Methods: A systematical literature search was done through the Medline database and seven related cohort studies were identified. The adjusted relative risks (RRs) with the highest and the lowest categories from each study were extracted to calculate the combined RR. A least-square trend estimation was applied to assess the dose-response relationships. Results: A combined RR of 0.86 (95% confidence interval (CI), 0.79-0.92) was revealed on T2DM risk associated to dairy intake, with little evidence of heterogeneity. For subgroup analysis, a combined RR was 0.82 (95% CI, 0.74-0.90), 1.00 (95% CI, 0.89-1.10), 0.95 (95% CI, 0.86-1.05) and 0.83 (95% CI, 0.74-0.93) for the intake of low-fat dairy, high-fat dairy, whole milk and yogurt, respectively. Dose-response analysis showed that T2DM risk could be reduced 5% for total dairy products and 10% for low-fat dairy products. Conclusion: An inverse association of daily intake of dairy products, especially low-fat dairy, with T2DM was revealed, indicating a beneficial effect of dairy consumption in the prevention of T2DM development. European Journal of Clinical Nutrition (2011) 65, 1027-1031; doi: 10.1038/ejcn.2011.62; published online 11 May 2011