Efficacy of curcumin/turmeric on liver enzymes in patients with non-alcoholic fatty liver disease: A systematic review of randomized controlled trials

Background: Several studies reported that curcumin supplementation could improve non-alcoholic fatty liver disease (NAFLD). The aim of this study was to evaluate the efficacy of curcumin/turmeric supplementation on liver enzymes in patients with NAFLD. Methods: PubMed, Scopus, Web of Science and Google Scholar were systematically searched until December 2017. We included randomized controlled trials (RCTs) which examined effect of curcumin/turmeric supplementation on NAFLD in adult participants. Main outcome was alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Potential risks of bias (ROB) were assessed by using Cochrane ROB tool. Results: All included studies showed low ROB in most of item of Cochrane ROB tool. Meta-analysis of 4 randomized controlled trials including 228 subjects showed a trend toward significant reduction of ALT blood concentrations in subgroup with >= 1000 mg/day curcumin supplementation (-11.36 IU/L, 95% CI: -22.75 to 0.02;I-2:51%). Meta-analysis showed a significant reduction of AST in studies with 8-weeks administration (-9.22 IU/L, 95% CI: -12.77 to -5.67; I-2: 49%). Conclusion: This review suggests that curcumin/turmeric might have a favorable effect on NAFLD in higher dosage. Further high-quality studies with large-scale and higher dosage are warranted. (C) 2018 Korea Institute of Oriental Medicine. Publishing services by Elsevier B.V.