Effect of Blended Antioxidant Supplement on Resting and Exercise-Induced Antioxidant Capacity and Oxidative Stress

Abstract

BACKGROUND: The in vivo ability to cope with the potentially damaging effects of reactive oxygen/nitrogen species through dietary interventions is of great interest to both scientists and consumers. PURPOSE: To determine the effects of a proprietary lipid and water soluble antioxidant blend on resting and exercise-induced blood antioxidant capacity and oxidative stress biomarkers in men and women. METHODS: 25 subjects (12 men; 13 women) received an antioxidant supplement or a placebo for 3 weeks in a random order, double blind, cross-over design (with a 3 week washout period). Blood samples were collected at rest, and at 0 and 30 minutes following a graded exercise treadmill test (GXT), both before and after each 3 week supplementation period. Blood samples were analyzed for Trolox Equivalent Antioxidant Capacity (TEAC), Oxygen Radical Absorbance Capacity (ORAC), malondialdehyde (MDA), hydrogen peroxide (H2O2), and nitrate/nitrite (NOx). RESULTS: Treatment with the supplement resulted in a significant increase in resting levels of blood TEAC (p=0.02) and ORAC (p=0.04). Although values for MDA and H2O2 were slightly lower, and values for NOx were slightly higher post intervention with the supplement, no statistically significant change was noted in resting levels of MDA, H2O2, or NOx (p>0.05). Exercise resulted in an increase in TEAC, ORAC, MDA, and H2O2 (p<0.05), all which were higher at 0 minutes post exercise compared to pre-exercise (p<0.05). No condition effects or condition interactions were noted for any variable in relation to the exercise bout (p>0.05). CONCLUSION: The antioxidant supplement significantly increased resting blood antioxidant capacity, with no statistically detected differences noted in resting oxidative stress biomarkers or in exercise-induced antioxidant capacity or oxidative stress biomarkers. Supported by Mannatech Inc.