Effects of resveratrol supplementation on liver enzymes: A systematic review and meta-analysis of randomised controlled trials

Background: The available evidence regarding the possible effects of resveratrol on liver function is inconsistent. Therefore, the present meta-analysis was performed to investigate the overall effects of resveratrol supplementation on liver enzymes in adults. Methods: A systematic and comprehensive search of the online medical databases including PubMed, Scupos, Web of Science and Cochran Library was performed up to February 2020. All RCTs using resveratrol supplements in adults were included in this systematic review and meta-analysis. The overall effect was presented as weighted mean difference (WMD) and 95% confidence interval (CI) in a random-effects meta-analysis model. Results: Finally, 15 randomised trials including 714 participants were selected for the present meta-analysis. Pooled analysis did not show any significant changes in alanine aminotransferase (ALT) (WMD: 0 IU/L, 95% CI: −3.17 to 3.17, P =.99; I² = 74.2%), aspartate aminotransferase (AST) (WMD: −2.40 IU/L, 95% CI: −5.45 to 0.65, P =.11; I² = 82.9%), gamma-glutamyl transferase (GGT) (WMD: −1.26 IU/L, 95% CI: −4.64 to 2.13, P =.64; I² = 23.7%), alkaline phosphatase (ALP) (WMD: 3.80 IU/L, 95% CI: −4.65 to 12.25, P =.37; I² = 29.9%) and bilirubin (WMD: 0.13 IU/L, 95% CI: −0.43 to 0.17, P =.39; I² = 8.9%) after supplementation with resveratrol. Conclusion: Overall, in our study, resveratrol does not affect liver enzyme levels significantly, but subgroup analysis indicates that these results may be influenced by resveratrol dose, duration of the study and population status, so future high-quality studies are necessary to get definitive results.