A dose-response evaluation of purified anthocyanins on inflammatory and oxidative biomarkers and metabolic risk factors in healthy young adults: A randomized controlled trial

Abstract Objective : Anthocyanins derived from different plant sources have been shown to possess a variety of health-promoting effects including anti-inflammatory properties and protection from oxidative stress. The aim of this study was to investigate the dose-response relationship between anthocyanins and metabolic risk factors as well as inflammatory and oxidative biomarkers in healthy adult volunteers. Methods : We conducted a randomized, double-blind, placebo-controlled trial, which included an increasing dosing schedule of 20, 40, 80, 160, and 320 mg of purified anthocyanins or placebo. Participants (n = 111) were administered either agent for 14 consecutive days. Results : No significant differences in either baseline characteristics or daily intake of dietary nutrients were detected between the experimental and control groups. After anthocyanin supplementation, there was a significant difference in adjusted fasting plasma glucose levels. The group receiving 80 mg/d of anthocyanin had the lowest baseline-adjusted fasting plasma glucose when compared with placebo (F = 3.556, P = 0.007). Logarithmically adjusted plasma interleukin-10 levels were negatively correlated with increasing anthocyanin dose (F = 2.738, P = 0.025). Similarly, 8-iso-prostaglandin F2α levels decreased with increasing anthocyanins dose (F = 3.513, P = 0.009). Conclusion : Taken together, our results suggest that anthocyanin supplementation at a dose above 80 mg/d is an effective anti-oxidant and anti-inflammatory agent in healthy young adults.