Antioxidant supplementation lowers exercise-induced oxidative stress in young overweight adults

Objective: To determine whether antioxidant (AOX) supplementation attenuates post-exercise oxidative stress and contributors to oxidative stress (inflammation, blood lipids) in overweight young adults. Research Methods and Procedures: This was a randomized, double-blind, controlled study. Overweight (BMI 33.2 +/- 1.9 kg/m(2)) and comparative normal-weight (BMI 21.9 +/- 0.5 kg/m(2)) adults 18 to 30 years old (total N = 48) were enrolled. Participants received either daily antioxidant (AOX) treatment (800 IU of vitamin E, 500 mg of vitamin C, 10 mg of beta-carotene) or placebo (PL) for 8 weeks for a total of four groups. All participants completed a standardized 30-minute cycle exercise bout at baseline and 8 weeks. Exercise-induced changes in lipid hydroperoxide (Delta PEROX), C-reactive protein (Delta CRP), interleukin-6 (Delta IL-6), cholesterol subtractions, triglycerides, total AOX status (Delta TAS), and adiponectin were assessed. Results: Exercise-induced Delta PEROX was lower in the over-weight-AOX group (0.09 nM/kg per min) compared with PL-treated overweight and normal-weight groups (0.98, 0.53 nM/kg per min) by 8 weeks (p < 0.05). Adiponectin was increased in both overweight and normal-weight AOX groups (22.1% vs. 3.1%; p < 0.05) but reduced in PL groups. Delta IL-6, Delta total cholesterol, and Delta low-density lipoprotein-chol esterol concentrations during exercise were lower in the AOX-treated groups compared with PL groups (all p < 0.05). After controlling for BMI, the Delta total cholesterol, Delta low-density lipoprotein-cholesterol, Delta adiponectin, and Delta TAS5 explained 59.1% of the variance of the regression model of the Delta PEROX by 8 weeks (total model R = 0.600; p = 0.015). Discussion: AOX lowers exercise-induced oxidative stress in overweight adults. Inflammatory and lipid markers may also be attenuated with AOX. Further studies are needed to determine whether AOX may be used in cardiovascular disease prevention in the overweight population.