PR_155: Antioxidant Supplementation Lowers Exercise-Induced Oxidative Stress in Young Overweight Adults

Abstract

Objective: To determine whether combined oral antioxidant supplementation can reduce postexercise oxidative stress and effects of contributors to oxidative stress (inflammation, blood lipids) in overweight young adults. Design: Randomized, double-blind, controlled study. Setting: Not provided. Participants: Overweight (body mass index [BMI], 33.2±1.9kg/m2) and comparative normal weight (BMI, 21.9±0.5kg/m2) adults aged 18 to 30 years (N=48) were provided a dietary intervention. Intervention: 8 weeks of daily antioxidant treatment (vitamin E, 800IU; vitamin, 500mg; beta-carotene, 10mg) or matched placebo. After fitness testing, all subjects completed a standardized 30-minute cycle exercise bout before and after the intervention period. Main Outcome Measures: Cycle exercise-induced changes in lipid peroxidation (ΔPEROX), inflammatory cytokines C-reactive protein, and interleukin-6 (ΔIL-6), and adiponectin, total cholesterol, cholesterol subfractions, and total antioxidant status (ΔTAS) at baseline and 8 weeks. Results: Exercise-induced ΔPEROX was significantly lower in the overweight antioxidant treatment group (.09nmol·kg−1·min−1) compared with placebo-treated overweight and normal weight groups (.98 and .53nmol·kg−1·min−1) by 8 weeks (P<.05). Adiponectin was increased in both overweight and normal weight antioxidant treatment groups, with the greater increase in the normal weight group at 8 weeks (22.1% vs 3.1%, P<.05), whereas adiponectin was reduced in both placebo groups. ΔIL-6, Δtotal cholesterol, and Δlow-density lipoprotein (LDL-C) concentrations during exercise were lower in both the antioxidant treatment groups compared with placebo groups (all P<.05). After controlling for BMI, Δtotal cholesterol, ΔLDL-C, Δadiponectin, and ΔTAS explained 59.1% of the variance of the regression model of the ΔPEROX by 8 weeks (total regression model R2=.600, P=.015). Conclusions: Antioxidant treatment supplementation is effective in lowering exercise-induced oxidative stress and, potentially, contributors to oxidative stress, more so in overweight adults. Inflammatory and lipid markers may also be attenuated with antioxidant treatment. Longer and larger studies are needed to determine whether antioxidant treatment may be used in cardiovascular disease prevention in the overweight population.