Background: Oxidative stress plays an essential role in the pathogenesis of type 2 diabetes. Anthocyanin, a natural antioxidant, has been reported to reduce oxidative stress and to attenuate insulin resistance and diabetes in animal models; however, the translation of these observations to humans has not been fully tested.
Objective: This study was designed to investigate the effects of purified anthocyanins on dyslipidemia, oxidative status, and insulin sensitivity in patients with type 2 diabetes.
Methods: A total of 58 diabetic patients were given 160 mg of anthocyanins twice daily or placebo (n = 29/group) for 24 wk in a randomized, placebo-controlled, double-blind trial. Participants and investigators were masked to treatment allocation.
Results: Anthocyanin supplementation significantly decreased serum LDL cholesterol (by 7.9%; P < 0.05), triglycerides (by 23.0%; P < 0.01), apolipoprotein (apo) B-48 (by 16.5%; P < 0.05), and apo C-III (by 11.0%; P < 0.01) and increased HDL cholesterol (by 19.4%; P < 0.05) compared with placebo after the 24-wk intervention. In addition, patients in the anthocyanin group showed higher total radical-trapping antioxidant parameter and ferric ion reducing antioxidant power values than did patients in the placebo group (both P < 0.05). Serum concentrations of 8-iso-prostaglandin F2α, 13-hydroxyoctadecadienoic acid, and carbonylated proteins in patients in the anthocyanin group were significantly less than in patients in the placebo group (23.4%, 25.8%; P < 0.01 and 20%; P = 0.022, respectively). Furthermore, supplementation with anthocyanin lowered fasting plasma glucose (by 8.5%; P < 0.05) and homeostasis model assessment for insulin resistance index (by 13%; P < 0.05), and elevated serum adiponectin (by 23.4%; P < 0.01) and β-hydroxybutyrate (by 42.4%; P = 0.01) concentrations compared with placebo supplementation.
Conclusion: These findings demonstrate that anthocyanin supplementation exerts beneficial metabolic effects in subjects with type 2 diabetes by improving dyslipidemia, enhancing antioxidant capacity, and preventing insulin resistance. This trial was registered at www.clinicaltrials.gov as NCT02317211.
Keywords: anthocyanin; antioxidant capacity; dyslipidemia; insulin resistance; type 2 diabetes.
© 2015 American Society for Nutrition.