Dairy Product Consumption in the Prevention of Metabolic Syndrome: A Systematic Review and Meta-Analysis of Prospective Cohort Studies

Previous meta-analyses have associated dairy products with a lower risk of metabolic syndrome (MetS). Since then, new studies evaluating not only total dairy but also different subtypes have been published in this field. The objective of the present work was to systematically review and meta-analyze the epidemiologic studies regarding the associations between the consumption of total dairy products and subtypes (milk, yogurt, and cheese) and the incidence of MetS. Relevant studies were identified through Medline and Cochrane databases. Eligible studies were prospective cohort studies that examined the association between dairy product consumption and/or different subtypes of dairy and the risk of MetS. Random-effects or fixed-effects models were assigned to calculate the pooled RR estimates with 95% CIs. From the 2994 identified articles, 12 and 11 studies were included for the qualitative and quantitative synthesis, respectively. After comparing the highest with the lowest categories, total dairy product consumption was inversely associated with the risk of MetS (9 study comparisons; RR: 0.73; 95% CI: 0.64, 0.83). Low-fat dairy and total yogurt consumption were inversely associated with the risk of MetS (low-fat dairy: 2 study comparisons; RR: 0.77; 95% CI: 0.65, 0.91; total yogurt consumption: 4 study comparisons; RR: 0.74; 95% CI: 0.66, 0.82). The linear RR per 1 serving of yogurt/d was 0.77 (95% CI: 0.60, 1.00). Low-fat yogurt and whole-fat yogurt were inversely associated with the risk of MetS (low-fat yogurt: 2 study comparisons; RR: 0.72; 95% CI: 0.62, 0.84; whole-fat yogurt: 2 study comparisons; RR: 0.81; 95% CI: 0.70, 0.94). Total milk consumption was inversely associated with the risk of MetS (6 study comparisons; RR: 0.79; 95% CI: 0.64, 0.97). Whole-fat dairy consumption was not associated with MetS risk. Our findings suggest that the consumption of total and low-fat dairy products, milk, and yogurt is inversely associated with the risk of MetS. The study protocol is available at https://www.crd.york.ac.uk/PROSPERO/ as CRD42018082480.