Association between dairy intake and the risk of contracting type 2 diabetes and cardiovascular diseases: a systematic review and meta-analysis with subgroup analysis of men versus women

Context: The association between dairy product intake and the risk of developing type 2 diabetes (T2D) or cardiovascular disease (CVD) has been investigated in several studies, but little attention was given to the role of sex as a moderator of these associations. (In this article, the term "sex" is used to denote the biologically-based differences between males and females.) Objective: This meta-analysis examines whether dairy consumption has different effects on T2D and CVD in men and women. Data sources: The PubMed database and previous reviews were searched for cohort studies published between 2006 and 2016. Data Extraction and Analysis: Reported risk ratios (RRs) for T2D/CVD with high versus low dairy intake were extracted. A random-effects model has been used to calculate the pooled RR. A subgroup analysis was conducted to compare the results for men and women. Results: The present meta-analysis of 201 studies found that T2D (n = 16 studies) and CVD (n = 13 studies) are inversely associated with dairy intake. Subgroup analysis for sex showed that the association between dairy intake and T2D and between dairy intake and CVD are significant in women (RR for T2D = 0.868; 95% CI, 0.82-0.92; P<0.001; RR for CVD = 0.837; 95% CI, 0.75-0.93; P<0.001) but not in men. Conclusions: There is an inverse association between high dairy intake and the risk of developing T2D and CVD in women.