Assessing Dietary Intakes Of Antioxidants And Aerobic Fitness Among Collegiate And Masters Athletes

Exogenous dietary antioxidants play a role in fighting reactive oxygen species. Their specific effects on aerobic fitness, however, are still largely unclear. PURPOSE: We evaluated dietary antioxidant intakes and their effects on aerobic fitness among female and male Collegiate and Masters Athletes. METHODS: In this cross-sectional study, we assessed the dietary intake of vitamins A, C and E, glutathione, and lutein-zeaxanthin, and their effects on aerobic fitness among Collegiate and Masters Athletes. Dietary intake was measured using a 2005 Block Food Frequency Questionnaire (FFQ). Aerobic fitness was assessed by maximal oxygen consumption (VO2max). RESULTS: A total of 135 Collegiate and Masters Athletes (71 females, 64 males; 35.9 ± 12.1 years of age) were included in the study. Collegiate male athletes had significantly greater total glutathione intake (55.7 ± 18.8 vs. 38.3 ± 13.7 mg/day; p = 0.011) and maximal oxygen consumption (VO2max) (48.4 ± 9.7 vs. 39.2 ± 3.9 mL oxygen/kg/minute; p = 0.005) compared to Collegiate female athletes. Similarly, Masters male athletes had significantly greater total glutathione intake (48.6 ± 18.9 vs. 40.5 ± 16.5 mg/day; p = 0.022) and VO2max (43.4 ± 10.2 vs. 35.8 ± 8.7 mL oxygen/kg/minute; p = 0.00011) compared to Masters female athletes. Masters female athletes had significantly higher lutein-zeaxanthin intakes (8,344.9 ± 5,659.1 vs. 6,015.8 ± 5,707.5 mcg/day; p = 0.043) compared to Masters male athletes. Intakes of vitamin A (r = 0.38, p = 0.032), vitamin C (r = 0.35, p < 0.05), and total glutathione (r = 0.53, p = 0.02) were positively correlated with VO2max among all Collegiate athletes. For all Masters Athletes, VO2max was positively correlated with total glutathione intake (r = 0.23, p = 0.019), but negatively correlated with vitamin A intake from supplements (r = -0.34, p = 0.0001). CONCLUSION: In general, Collegiate and Masters male athletes had significantly greater intakes of antioxidants through dietary sources and supplements compared to female athletes; though Masters female athletes had higher lutein-zeaxanthin intakes compared to Masters male athletes. Our data suggest that glutathione intake may have positive effects on aerobic fitness. Prospective studies need to be conducted to investigate glutathione intake and its role in improving aerobic fitness in athletes.