Purpose:The purpose of this study was to compare the effects of two antioxidant formulas on biomarkers of oxidative stress before and after aerobic exercise.

Methods: Aerobically trained men and women were assigned to one of three treatments: 1) 400 IU of vitamin E plus 1 gram of vitamin C (V treatment), or 2) a fruit and vegetable juice powder concentrate (FV treatment), or 3) a placebo (P treatment). Subjects ran for 30 minutes at 80% VO2max before, after 2 weeks of supplementation, and after a 1-week 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 weeks, with no change in the FV or P. Postexercise PC values elevated for all treatments after all exercise bouts. Both V and FV attenuated the exercise-induced increase in PC after 2 wek of supplementation; and after the 1 week washout compared with the P treatment with no differences between V and FV. MDA was unaffected by exercise and treatment. No exercise session or time main effect was noted for 8-OHdG, suggesting theat the lower mean value for the V treatment group was not a result of the supplementation.

Conclusion: These data suggest that V and FV supplmentation for 2 weeks can attenuate the rise in PC after 30 minutes of aerobic exercise, even after a 1-week washout, without an impact on plasma MDA or 8-OHdG.

Discussion Summary: In conclusion, it was shown that antioxidant supplementation with vitamin C plus E or a mixed fruit and vegetable juice concentrate can attenuate the rise in protein oxidation observed after an acute 30-minute run at 80% VO2max. This exercise resulted in no change in plasma MDA or 8-OHdG. It should be noted that despite the effect of the two antioxidant treatments on post exercise protein oxidation, supplementation did not eliminate the elevation in protein carbonyl values, but rather reduced this slightly. Furthermore, the antioxidant supplements did not have an impact on exercise-associated variables (e.g. heart rate and perceived exertion), although performance variables were not measured in the present study. Taken together with the MDA and 8-OHdG data, it appears as though antioxidant supplementation within a population of aerobically trained men and women demonstrates only modest protection for protein oxidation, with little impact on other markers. This is truth for both the FV as well as the V treatment. It is believed that antioxidants other than vitamin C and E could have provided protection against protein oxidation, but further research is warranted to determine which phytonutrients were involved. The finding that supplementation with a fruit and vegetable juice concentrate can provide protection against exercise induced oxidative stress in a similar manner as higher dosages of vitamins C and E deserves attention. This is true especially in light of the recent report suggesting adverse health outcomes with higher-dose, long-term vitamin E supplementation, a routine practice.

Opinion: With the lack of fruit and vegetable intake in the majority of diets across the US and around the world, the proper nutrition is not being acquired to support a healthy diet in the prevention of sickness and disease. One option for helping get the nutrients needed is a fruit and vegetable juice powder concentrate, plus the option to get the concentrate in a capsule makes it easier to add to an individual's diet.

DISCLAIMER: Please consult your physician when beginning any weight loss or exercise program.