Effects of non-soy legume consumption on C-reactive protein: A systematic review and meta-analysis

Objectives: Because of conflicting results of presented studies, the aim of this systematic review and meta-analysis of randomized clinical trials (RCTs) was to examine the effect of non-soy legume intake on inflammatory markers and C-reactive protein (CRP). Methods: We searched Pubmed, ISI Web of Knowledge, SCOPUS, and Google Scholar for relevant studies up to July 2013, using medical subject headings [MeSH] and other related keywords. Nine RCTs were systematically reviewed to examine the effect of non-soy legume consumption on inflammatory markers. Eight studies involving 464 participants were included in the meta-analysis. Results: The results of the meta-analysis showed that non-soy legume consumption had a trend toward a significant effect on decreasing CRP and high-sensitivity (hs)-CRP concentrations (mean difference (MD) = -0.21; 95% confidence interval [CI], -0.44 to 0.02; P = 0.068). There was no overall effect of non-soy legume consumption on CRP or hs-CRP levels in either the parallel or crossover study designs. Our subgroup analysis of CRP type and study design, showed that non-soy legume intake had a significant effect on CRP levels in parallel studies (MD = -1.01; 95% CI, -1.78 to -0.23; P = 0.011) and a significant effect on hs-CRP levels (MD = -0.53; 95% CI, -0.95 to -0.11; P = 0.014) and in the crossover sub group (MD = -0.68; 95% Cl, -1.28 to -0.08; P = 0.026). Conclusions: This review of RCTs showed that non-soy legume consumption may contribute to reductions in CRP and hs-CRP concentrations. However, further controlled clinical trials are needed to investigate the effect of non-soy legume intake on other inflammatory markers. (C) 2015 Elsevier Inc. All rights reserved.