Relationship between legume consumption and metabolic syndrome: A systematic review and meta-analysis of observational studies.

AIMS: The prevalence of metabolic syndrome (MetS) has been increasing in recent years. Investigation of whether consumption of legumes as a part of healthy diet could reduce the odds of MetS has led to inconsistent conclusions. Here, we performed the first meta-analysis of observational studies to analyze the association between legume consumption and prevalence of MetS. DATA SYNTHESIS: PubMed, EMBASE, and Web of Science databases were searched to identify observational studies up to June 1, 2019. We extracted data from the studies included and performed quality assessments. Summary odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using a random-effects model. Publication bias and subgroup and sensitivity analyses were also performed. We finally included four cross-sectional studies, two cohort studies, and one case-control study involving 56,028 participants. The summary OR revealed no statistically significant association between legume consumption and odds of MetS (OR = 0.93, 95% CI = 0.76-1.12, I2 = 73.5%). Subgroup analysis of study characteristics and adjustment for confounding along with sensitivity analyses revealed no statistically significant differences. No evidence of publication bias was detected. CONCLUSION: Legume consumption is not associated with the odds of MetS. These findings require validation in well-designed cohort studies and randomized clinical trials with accurate measurement of legume intake and strict control of confounders. REGISTRATION: This study was registered with the International Prospective Register of Systematic Reviews (registration number: CRD42019131777).