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% VO(2 max) 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 <or= 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, 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.
RCT Entities:
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% VO(2 max) 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 <or= 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, 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.