Soy diet for nonalcoholic fatty liver disease: A meta-analysis of randomized controlled trials

INTRODUCTION: The efficacy of soy diet for nonalcoholic fatty liver disease remains controversial. We conduct a systematic review and meta-analysis to explore the influence of soy diet vs placebo on the treatment of non-alcoholic fatty liver disease. METHODS: We search PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases through October 2020 for randomized controlled trials assessing the efficacy of soy diet vs placebo for nonalcoholic fatty liver disease. This meta-analysis is performed using the random-effect model. RESULTS: Five randomized controlled trials are included in the meta-analysis. Overall, compared with control group for nonalcoholic fatty liver disease, soy diet is associated with significantly reduced HOMA-IR (standard mean difference [SMD] = −0.42; 95% confidence interval [CI] = −0.76 to −0.08; P = .01), increased insulin (SMD = −0.64; 95% CI = −0.98 to −0.30; P = .0002) and decreased malondialdehyde (SMD = −0.43; 95% CI = −0.74 to −0.13; P = .005), but demonstrated no substantial impact on body mass index (SMD = 0.17; 95% CI = −0.20 to 0.53; P = .37), alanine aminotransferase (SMD = −0.01; 95% CI = −0.61 to 0.60; P = .98), aspartate-aminotransferase (SMD = 0.01; 95% CI = −0.47 to 0.49; P = .97), total cholesterol (SMD = 0.05; 95% CI = −0.25 to 0.35; P = .73) or low density lipoprotein (SMD = 0; 95% CI = −0.30 to 0.30; P = .99). CONCLUSIONS: Soy diet may benefit to alleviate insulin resistance for nonalcoholic fatty liver disease.