Med Sci Sports Exerc. 2016 Jan 13. [Epub ahead of print]

Effect of Docosahexaenoic Acid on a Biomarker of Head Trauma in American Football.

Oliver JM1, Jones MT, Kirk KM, Gable DA, Repshas JT, Johnson TA, Andréasson U, Norgren N, Blennow K, Zetterberg H.

Author information

• 11Sports Concussion Research Group, Department of Kinesiology, Texas Christian University, Fort Worth, TX; 2Division of Health and Human Performance, George Mason University, Manassas, VA; 3Department of Sport Medicine, Texas Christian University, Fort Worth, TX; 4Department of Sport Medicine, John Peter Smith Hospital, Fort Worth, TX; 5UmanDiagnostics, Umeå, Sweden; 6Clinical Neurochemistry Laboratory, Institute Of Neuroscience and Physiology, the Sahlgrenska Academy at University of Gothenburg, Mölndal, Sweden; 7Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, United Kingdom.

Abstract

PURPOSE:

American football athletes are exposed to sub-concussive impacts over the course of the season resulting in elevations in serum neurofilament light (NFL), a biomarker of axonal injury. Docosahexaenoic acid (DHA) has been reported to reduce axonal trauma associated with traumatic brain injury in rodent models. However, the optimal dose in American football athletes is unknown. This study examined the effect of differing doses of DHA on serum NFL over the course of a season of American football.

METHODS:

In a randomized, double-blind, placebo-controlled, parallel design eighty-one (n = 81) National Collegiate Athletic Association (NCAA) Division I American football athletes were assigned to ingest either 2 g•d, 4 g•d, 6 g•d of DHA, or placebo. Blood was sampled at specific times over the course 189 days coincident with changes in intensity, hours of contact, and likely changes in head impacts. Standardized magnitude-based inference was used to define outcomes.

RESULTS:

DHA supplementation increased plasma DHA in dose-dependent manner (mean difference from baseline; ± 90% CL; 2 g•d: 1.3; ±0.6; 4 g•d: 1.6; ±0.7%; 6 g•d: 2.8; ±1.2%). Serum NFL increased to a greater extent in starters (AUC, 1995 ± 1383 pg•mL•day) versus non-starters (1398 ± 581 pg•mL•day; p = 0.024). Irrespective of dose, supplemental DHA likely attenuated serum NFL coincident with increases in serum NFL by likely small and moderate magnitude (ES = 0.4 to 0.7).

CONCLUSION:

Findings from this study, the first large scale study examining potential prophylactic use of DHA in American football athletes, include identification of optimal dose of DHA suggest a neuroprotective effect of DHA supplementation.