Evidence Of Oxidative Stress And Persistent Inflammation In American-Style Football Players

PURPOSE: Oxidative stress (OS), the imbalance between reactive oxygen & nitrogen species and antioxidant capacity, is a trigger for inflammation. OS and inflammation develop transiently after acute exercise, but little is known about how OS may co-exist with chronic inflammation among athletes. Because chronic inflammation may affect both athletic performance and long-term health, we sought to evaluate in-season inflammation and OS in collegiate American-style football (ASF) athletes, comparing linemen (LM) to non-linemen (NL). METHODS: Fingerstick capillary blood samples (8/participant) were obtained from healthy ASF athletes at two Division I colleges, sampling twice/week, biweekly during the competitive season to assess high sensitivity C-reactive protein (hsCRP) and the OS index (OSI = hydroperoxides/total antioxidant capacity). Participants were surveyed regarding recent illness, injury, concussion, energy levels and muscle soreness at each visit. Group differences were assessed with unpaired t-tests, Mann-Whitney U tests, and chi squared tests as appropriate for data distribution. RESULTS: Amongst 50 participants, 32 (64%) were NL and 18 (34%) were LM. OSI and hsCRP were positively associated (r = 0.28, p < 0.0001). Heightened inflammation was more common in LM (TABLE), with elevated median hsCRP ≥2 mg/L in 10 (56%) LM vs. only 5 (16%) NL (p = 0.009). OSI was also higher in LM vs. NL (1.77 ± 0.35 vs. 1.47 ± 0.36, p = 0.007), driven by both higher hydroperoxides and lower antioxidants. Incidence of illness, injury, and concussion did not differ in LM vs. NL. CONCLUSIONS: Amongst ASF players, more than half of LM demonstrate persistently elevated levels of inflammation, which are related to higher OS and not explained by higher incidence of illness or injury. Given the potential long-term impact of chronic inflammation and its relationship with OS, interventions that target reduction of OS (e.g. nutritional) may also reduce inflammation in at-risk athletes. This work was completed by the Harvard Football Players Health Study and funded by the National Football League Players Association.