Dairy consumption and risk of metabolic syndrome: A meta-analysis

Aims: To conduct a systematic review and meta-analysis of epidemiological studies in order to assess quantitatively the effect of dairy consumption on risk of metabolic syndrome. Methods: We searched for eligible studies published up to March 2015 through the PubMed and Embase databases and reviewed the references of relevant articles. Random-effects models were used to calculate the pooled relative risks with 95% CIs after adjusting for several confounders. Results: We identified nine prospective cohort studies including a total of 35 379 subjects and 7322 incident cases of metabolic syndrome, and 12 cross-sectional studies including 37 706 subjects. In the meta-analysis of prospective cohort studies, the pooled relative risk of incidence of metabolic syndrome for the highest vs. the lowest category of dairy consumption was 0.85 (95% CI 0.73-0.98), and for a 1-serving/day increment of dairy consumption, the pooled relative risk was 0.88 (95% CI 0.82-0.95). In the meta-analysis of cross-sectional studies, the pooled relative risk of prevalence of metabolic syndrome for the highest vs. the lowest category of dairy consumption was 0.73 (95% CI 0.63-0.86). The association was not significantly different by geographical region, follow-up time and adjustment factors. Conclusion: Our findings indicate that dairy consumption is inversely associated with the incidence and prevalence of metabolic syndrome. Further well-designed cohort studies and randomized controlled trials are warranted to provide definitive evidence.