Abstract

Background: Several mechanisms have been suggested to explain the pathogenesis of nonalcoholic fatty liver disease (NAFLD) and its progression, one of which is increased oxidative stress. Objectives: This study aimed to evaluate the effect of alpha-lipoic acid (ALA) supplementation on anthropometric indices, dietary intake and oxidative stress-related parameters in obese patients with NAFLD. Methods: In this double-blind, placebo-controlled trial, 50 NAFLD patients were assigned to two groups of receiving 1200 mg ALA (two 600 mg capsules of ALA) and placebo (two 600 mg capsules of placebo) for 12 weeks. Serum liver enzymes, malondialdehyde (MDA) level, total antioxidant status (TAS), and the activities of copper-zinc superoxide dismutase (Cu/Zn-SOD) and glutathione peroxidase (GSH-Px) were assessed at baseline and after 12 weeks of intervention. Results: Serum concentrations of liver enzymes decreased significantly in the ALA group (P < 0.05 for all), while a noticeable decline was observed for alanine aminotransferase (ALT) in the placebo group (32.5 +/- 18.9 vs. 25.9 +/- 11.2; P = 0.034). Nonetheless, there were no significant differences between the study groups concerning serum liver enzymes concentrations post-intervention. Although ALA supplementation significantly reduced the serum concentration of MDA (2.52 +/- 0.35 vs. 2.77 +/- 0.49; P < 0.040) and increased serum TAS (1.73 +/- 0.55 vs. 1.52 +/- 0.34; P < 0.048), other oxidative stress-related parameters such as Cu/Zn-SOD and GSH-Px activities were not affected. Conclusions: These findings suggest that daily supplementation of 1200 mg alpha-lipoic acid (ALA) for 12 weeks improves oxidative stress markers in patients with nonalcoholic fatty liver disease (NAFLD) and it could be considered as adjunctive therapy for the prevention of NAFLD progression.