Purpose: To compare the effects of two antioxidant formulas on biomarkers of oxidative stress before and after aerobic exercise.
Methods: Aerobically trained men (N = 25) and women (N = 23) were assigned to one of three treatments: 400 IU of vitamin E + 1 g of vitamin C (V; N = 15), a fruit and vegetable juice powder concentrate (FV; N = 16), or a placebo (P; N = 17). Subjects ran for 30 min at 80% V̇2max before, after 2 wk of supplementation, and after a 1-wk washout period. Blood samples were taken before and immediately after exercise and analyzed for protein carbonyls (PC), malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), and vitamins C and E.
Results: The V treatment increased plasma vitamin C and E after 2 wk (P ≤ 0.05), with no change in the FV or P. Postexercise PC values were elevated for all treatments after all exercise bouts (P < 0.0001). Both V and FV attenuated the exercise-induced increase in PC after 2 wk of supplementation (V = 21%, FV = 17%), and after the 1-wk washout (V = 13%, FV = 6%) compared with P (P < 0.05), with no differences between V and FV. MDA was unaffected by exercise and treatment. A treatment main effect for 8-OHdG was noted, with values for V lower than for FV and P (4.5 ± 2.5, 5.5 ± 2.7, and 6.0 ± 2.5 ng·mL−1, respectively; P = 0.0002). No exercise session or time main effect was noted for 8-OHdG, suggesting that the lower mean value for the V treatment group was not a result of the supplementation.
Conclusion: These data suggest that V and FV supplementation for 2 wk can attenuate the rise in PC after 30 min of aerobic exercise, even after a 1-wk washout, without an impact on plasma MDA or 8-OHdG.
1Department of Health and Sport Sciences, University of Memphis, Memphis, TN; and 2Exercise Physiology Laboratory, Department of Exercise and Sport Science, University of North Carolina Greensboro, Greensboro, NC
Address for correspondence: Richard J. Bloomer, Department of Health and Sport Sciences, 161F Elma Neal Roane Field House, The University of Memphis, Memphis, TN 38152; E-mail: email@example.com.
Submitted for publication June 2005.
Accepted for publication December 2005.