Alpha-lipoic acid supplement in obesity treatment: A systematic review and meta-analysis of clinical trials

Abstract

BACKGROUND & AIMS: Previous studies have supported positive roles of antioxidant supplements on weight-loss. One antioxidant supplement is Alpha-lipoic acid. However, recommending ALA as an anti-obesity supplement remains controversial. Accordingly, the purpose of the present study was to perform a meta-analysis on the effects of ALA supplement on anthropometric indices among adult subjects. METHODS: We searched five electronic databases till September 2016. Placebo-controlled clinical trials were included. Weighted Mean Difference (WMD) was pooled using a random-effects model. RESULTS: Findings of 12 included trials indicated that ALA supplement reduced body weight (WMD: -0.69 kg; 95 CI: -1.27, -0.10; I(2) = 0) and BMI (WMD: -0.38 kg/m(2); 95 CI: -0.53, -0.24; I(2) = 0) significantly compared to the placebo group. However, its effects on Waist Circumference (WC) was not significant (WMD: -0.30 cm; 95 CI: -1.18, 0.58; I(2) = 17.8). Stratification by health status indicated that ALA decreased WC in unhealthy subjects (WMD: -2.00 cm; 95 CI: -4.19, 0.19; I(2) = 1.3) more than healthy individuals (0.03 cm; 95 CI: -0.69, 0.75; I(2) = 0). CONCLUSIONS: The present study revealed that supplementation with ALA slightly but significantly decreased body weight and BMI. Safe dosage for ALA is up to 1200 mg/day. However, it seems that ALA cannot be cost-effective. Further studies are needed to clarify the effects of ALA on metabolic parameter in unhealthy obese individuals.