The Effects of Antioxidant Consumption on Inflammation and Muscle Soreness at Moderate Altitude in Collegiate Football Student-Athletes

Abstract

Introduction: Athletics training and competition is associated with increased oxidative stress and inflammation, especially at moderate altitude. This results from an increased formation of reactive oxygen species due to increased metabolic activity of working cells and tissues as well as decreased oxygen pressure. The oxidative stress can cause inflammation and delayed onset muscle soreness (DOMS), which can be a serious problem for athletes training and competing at a high caliber, as it interferes with optimal sport performance and recovery. A diet intervention was developed to study the relationship between antioxidant-rich food consumption and implications per reduced inflammation and DOMS among athletes. Methods: During summer 2021, 32 NCAA Division 1 collegiate football student-athletes living and training at moderate altitude were recruited to participate in a seven-week nutrition intervention. Participants were assigned to either an intervention or control group. Participants in the intervention group consumed at least 10,000 Oxygen Radical Absorbance Capacity (ORAC) score units per day through an antioxidant-rich trail mix constructed by the research team. Participants consumed this trail mix in addition to their normal diet. Participants in the control group did not receive trail mix and continued their normal diet. Inflammation was measured pre- and post- intervention through blood biomarkers (high sensitivity C-reactive protein, hs-CRP; Interleukin-6, IL-6) and urine sample analysis (Isoprostane Creatinine ratio, F2/C). DOMS was measured through a pre- and post- survey (Numerical Pain Rating Scale, NPRS). Results: An independent samples T-test identified the change in mean ORAC scores for the intervention group (M±SD, 149121 units ± 18357 units) was statistically higher than the change in mean ORAC score for the control group (28391 units ± 15359 units): t(30)=-20.02, p<.001. Paired samples T-tests indicated that hs-CRP and F2/C did not change significantly between time 1 (hsCRP: 1.31 mg/dL ±1.28 mg/dL) (F2/C: 0.41 ± 0.23) and time 2 (hsCRP: 1.50 mg/dL ± 1.92 mg/dL) (F2/C: 0.42 ± 0.11). Separate regression analyses identified pre- F2/C as a significant predictor of post- F2/C for the control group (B=0.399, p<0.001) and mean ORAC score as a significant predictor of post- F2/C for the intervention group (B=-3.604E-6, p=0.028). Repeated measures ANOVA indicated no significant effect of time (F(1,27)=0.399, p=.533), or group by time (F(1,27)=0.521, p=.477) on DOMS. Conclusions: Antioxidant-rich food consumption had minimal impact on inflammation or DOMS induced by physical exercise at moderate altitude among this sample of collegiate football student-athletes. Future research is required to assess the relationship between antioxidant consumption and implications per reduced inflammation and DOMS for student-athletes participating in other collegiate sports.