Effects of garlic supplementation on liver enzymes: A systematic review and meta‐analysis of randomized controlled trials

Current evidence on the beneficial effects of garlic on liver enzymes is contradictory. Therefore, the aim of this systematic review and meta‐analysis is to evaluate the effect of garlic supplementation on human liver enzymes, such as Alanine Transaminase (ALT/SGPT) and Aspartate Transaminase (AST/SGOT). To collect the required data, PubMed, Scopus, ISI Web of Science, and Google scholar databases were systematically searched from inception to June 2019. A meta‐analysis was conducted using the random‐effects model to evaluate the effects of garlic supplementation on ALT and AST levels. The Cochran's Q‐test and inconsistency index were also used to evaluate heterogeneity among the studies. Among a total of 15,514 identified articles, six studies (containing 301 participants) met the inclusion criteria. Results of the meta‐analysis showed that garlic supplementation significantly decreased AST level (Hedges' g = −0.36, 95% confidence interval [CI]: −0.72, −0.004, p = .047); whereas, it had no significant effect on ALT level (Hedges' g = −0.22, 95% CI: −0.64, 0.20, p = .310). Results showed that garlic supplementation reduced AST levels significantly; however, had no significant effect on ALT levels. Further studies are still needed to confirm the results.