Antioxidant effects of curcuminoids in patients with type 2 diabetes mellitus: a randomized controlled trial

Oxidative stress has a key role in the pathogenesis of type II diabetes mellitus (T2DM) and its vascular complications. Antioxidant therapy has been suggested as a potential approach to blunt T2DM development and progression. The aim of this study was to assess the effects of supplementation with curcuminoids, which are natural polyphenolics from turmeric, on oxidative indices in diabetic individuals. In this randomized double-blind placebo-controlled trial, 118 subjects with T2DM were randomized to curcuminoids (1000 mg/day co-administered with piperine 10 mg/day) or matching placebo for a period of 8 weeks. Serum total antioxidant capacity, superoxide dismutase (SOD) activities and malondialdehyde (MDA) concentrations were measured at baseline and after the supplementation period. Curcuminoids supplementation caused a significant elevation in serum total antioxidant capacity (TAC) (p < 0.001) and SOD activities (p < 0.001), while serum MDA levels were significantly reduced compared with the placebo group (p < 0.001). These results remained statistically significant after adjustment for potential confounders (baseline differences in body mass index and fasting serum insulin). The present results support an antioxidant effect of curcuminoids supplementation in patients with T2DM, and call for future studies to assess the impact of these antioxidant effects on the occurrence of diabetic complications and cardiovascular endpoints.