The effects of green coffee bean extract supplementation on lipid profile in humans: A systematic review and meta-analysis of randomized controlled trials

Background and aim: This systematic review and meta-analysis aimed to assess the effects of green coffee bean extract (GCBE) supplementation on lipid profile in adults. Methods and results: The PubMed/Medline, Scopus, Web of sciences, and Google Scholar were systematically searched for randomized controlled trials available in English and published before February 2019. The meta-analysis was conducted using fixed effects models, and between-study heterogeneity was assessed by Cochran's Q test and I2. A total of 17 effect sizes were included in the meta-analysis. Combined effect sizes on serum total cholesterol concentrations revealed significant effects of GCBE supplementation on serum total cholesterol [weighted mean difference (WMD): -4.51 mg/dL, 95% confidence interval (CI): -6.89, -2.12, p < 0.001], low density lipoprotein-cholesterol (LDL-C) (WMD: -4.38 mg/dL, 95% CI: -6.44, -2.31, p < 0.001), and high density lipoprotein-cholesterol (HDL-C) (WMD: 2.63 mg/dL, 95% CI: 2.20, 3.07, p < 0.001) compared to controls. Nevertheless, no significant changes were observed in serum triglycerides levels (WMD: -4.34 mg/dL, 95% CI: -9.00, 0.32, p = 0.068). Conclusion: The evidence from available studies suggests that the GCBE supplementation leads to significant reductions in total cholesterol, HDL-C, and LDL-C levels, and has modest, but, non-significant effects on triglycerides levels