Background – Exercise is known to increase the production of reactive oxygen species (ROS)[1]. Dietary carotenoids have antioxidant properties and may possess anti-inflammatory effects [2].
Objective – The objective of the study was to determine the effect of dietary antioxidant restriction on short- duration maximal exhaustive exercise induced markers of inflammation, carotenoids and fatty acids in healthy male endurance athletes.
Design – Seventeen endurance-trained athletes performed two separate exercise tests. Participants followed their habitual (high) antioxidant diet (HA) and performed an overnight fasting treadmill exercise test. Participants then followed a reduced antioxidant diet (RA) for 2 weeks and then performed the same overnight fasting treadmill exercise test. Blood was collected at rest and post-exercise for the analysis of inflammatory markers, fatty acids and carotenoids in plasma.
Outcomes – The RA diet induced a significant increase (P<0.01) in baseline plasma TNF-alpha concentration (612.86 + 325.23 ng/ml) compared to the HA diet (28.30 + 39.07 ng/ml). Baseline plasma beta-carotene concentration significantly decreased (P<0.05) in the RA diet (122.61 + 54.49 ng/ml) compared to the HA diet (194.96 + 92.07 ng/ml). Exercise decreased plasma carotenoid concentrations in both diets. Exercise significantly decreased (P<0.01) plasma n-6 fatty acid concentration in the RA diet (186.38 + 94.54, 96.16 + 48.76 μg/ml) and increased (P<0.05) plasma n-3 fatty acid concentration in the HA diet (14.27 + 5.04, 18.63 + 4.94 μg/ml). Conclusion – Healthy endurance-trained adults performing short-duration exhaustive exercise may require higher intakes of carotenoids to combat oxidative stress and inflammation generated through exercise, which can be achieved via a diet containing high-carotenoid foods.
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