Effect Of Avenanthramide Supplementation On Responses To Eccentric Exercise In Young Women

Abstract

Avenanthramides (AVA) are a group of nitrogen-containing diphenolic phytochemicals found exclusively in oats that have exhibited antioxidant and anti-inflammatory potential in vitro and in rodents; however, the effects of chronic AVA consumption in humans have been unexplored. PURPOSE: To investigate the effects of 8 weeks of AVA supplementation on the inflammatory and oxidative responses to a single bout of downhill running in college-aged women. METHODS: Ten women aged 18-29 yr were randomly assigned to receive cookies fortified with either high-AVA (23.5 mg/day) oat flour (O, Ceapro Inc., Canada) or with equal content of wheat flour as a placebo (PL). They were instructed to eat one 115 g cookie per day for 8 wks, during which dietary and physical activity levels were recorded. Before and after the supplementation period, subjects ran on a treadmill at -9% grade at a speed that elicited 75% of their maximal heart rate for 4 x 15 min bouts with 3 rest intervals of 5 min each. Blood samples were collected before and immediately and 24-h post exercise. RESULTS: There was no difference in pain and soreness ratings between O and PL groups post-exercise. During the post-supplementation test, O showed a higher plasma reduced to oxidized glutathione ratio (P<0.05) at 24 h post-exercise vs. PL group. Red blood cell (RBC) glutathione peroxidase activity decreased (P<0.05) immediately after exercise in O, but not in PL. RBC superoxide dismutase activity was higher (P<0.05) in O vs. PL post-exercise. There were trends toward lower plasma tumor necrosis factor (TNF)-alpha levels and white blood cell reactive oxygen species production in O compared to PL immediately and 24-h after exercise. CONCLUSIONS: High-AVA oat supplementation appears to attenuate downhill exercise-induced oxidative stress and blood inflammatory markers in college-aged women.