The effects of docosahexaenoic acid and eicosapentaenoic acid on biomarkers of sub‐concussive injury in National Collegiate Athletic Association Division 1 American football players

Abstract

Participation in American football has been associated with repeated head impacts (RHI) and an increase in risk of concussive injury also called mild traumatic brain injury (mTBI). Elevated neurofilament light (NfL), a biomarker of axonal injury, has been shown to be a sensitive marker for both mTBI and sub-concussive brain injury in contact sports. Omega-3 polyunsaturated fatty acids, including docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), have been reported to reduce inflammation, protecting against nerve damage, stimulating neuronal growth, and promoting recovery following head injury. Here we performed a randomized, placebo-controlled, double-blinded, parallel group design trial to determine the potential impact of DHA/EPA supplementation on serum NfL in National Collegiate Athletic Association (NCAA) Division I American football athletes (n=38). Players (both starters and nonstarters) were assigned to either 3.0 g/d DHA/EPA or placebo groups, and blood was sampled at baseline and throughout the football season from no contact conditioning to the last in-season scheduled game. DHA/EPA supplementation markedly increased plasma DHA levels from baseline at four time points (p<0.000001 at time point (T) 2; p<0.0001 at T3; p<0.001 at T4; and p<0.01 at T5). Additionally, serum NfL increased in all participants (starters and nonstarters) during conditioning and early season (p<0.001), and this upward trend continued in starters throughout the season (p<.05). There was no impact of DHA/EPA supplementation on serum NfL levels in either group tested. This study confirms results from previous studies which show an increased circulating NfL level in players who spent the greatest amount of time on the field in games (starters). However, it did not corroborate previous findings that DHA/EPA supplementation attenuates the increase in NfL levels in either group. Important limitations of this study include the small sample size and heterogeneous group of football players. This study supports the need for effective strategy to protect American football participants from brain injury.