A Systematic Review and Meta-Analysis of the Effects of Soy on Serum Hs-Crp Publisher Pubmed



Khodarahmi M^{1, 2} ; Jafarabadi MA^{3, 4} ; Moludi J⁵ ; Abbasalizad Farhangi M^{6, 7}
Source: Clinical Nutrition Published:2019

Abstract

Background & aim: The results of studies about the effect of soy products on serum highly sensitive C-reactive protein (hs-CRP) are inconsistent. The aim of this systematic review and meta-analysis of randomized clinical trials (RCTs) was to investigate the effect of soy products intake on serum hs-CRP concentration. Methods: We searched PubMed, EMBASE, Science Direct, ISI Web of Science, Google Scholar and Cochrane Central Register of Controlled Trials up to December 2016 without language restrictions. Random-effect model was used for quantitative data synthesis. Results: Thirty-six studies were included in our analyses. A meta-analysis revealed a non-significant reduction in serum hs-CRP concentrations following soy products consumption, −0.19 (mg/L) (95% CI: −0.49 to 0.09; I 2 = 95.6%). Subgroup analyses suggested that natural soya products may reduce plasma levels of CRP by −0.18 mg/L (95% CI: −0.28 to −0.08; I 2 : 11.6) in comparison to other source of isoflavones (soya extracts, supplements). Moreover, the effect was stronger among subjects with baseline hs-CRP concentrations of less than 2.52 mg/L, −0.15 (95% CI: −0.27 to −0.02; I 2 : 34.6). A meta-regression analysis revealed that dosage of isoflavones seems to be a strong predictor of the effect of soya on serum hs-CRP levels. Conclusion: Present review of RCTs published up to December 2016 did not provide strong evidence regarding the beneficial effect of soya products consumption on blood hs-CRP concentrations. However, it appears that natural soya products may reduce plasma levels of hs-CRP in comparison to other source of isoflavones. Large and well-designed studies are recommended to confirm this conclusion. Systematic review registration: PROSPERO CRD42018069371. © 2018 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism