With football season looming closer, there’s mounting evidence that there’s reason to step back and seriously re-consider whether it’s a good idea to play. A paper, published Tuesday in the journal Frontiers of Neurology, stacked more evidence on the dangerous impact of sports-related concussions damaging the brain, suggesting that age plays no role in being immune to brain injuries.

Unlike previous research focusing on professional athletes, this new paper suggests brain damage begins worrisomely early, with teenagers who’ve suffered from concussions showing evidence of brain damage, regardless of gender.

“These findings indicate persistent differences in brain physiology for athletes participating in contact and collision sports, which should be considered in future studies of concussion and subconcussive impacts,” the researchers write. “While the majority of athletes who participate in collision and contact sports do not present with debilitating clinical outcomes, there is growing concern for the long-term brain health of these athletes.”

Doctors at the Neuroscience Research Program at St. Michael’s Hospital in Toronto conducted the study using advanced magnetic resonance imaging (MRI) to evaluate the brain physiology of three groups of varsity athletes: 23 who play collision sports that involved routine, body-to-body contact, 22 from contact sports, and 20 from non-contact sports. Brain scan analysis revealed that the athletes who played in collision and contact sports had notable differences in their brain structure, compared to athletes who did not play in contact sports. Specifically, the athlete’s brain’s white matter, the fibre tracts that help different parts of the brain communicate with each other, suffered. Participants who played in sports with higher levels of contact had reduced levels of communication and decreased activity in the parts of the brain associated with vision and motor function. These athletes also had the chemical markers that are typically associated with brain injury.

A normal brain compared to one with severe CTE. 

Previous research on the brains of deceased, former NFL players found that 110 out of 111 brains — 99 percent — had evidence of chronic traumatic encephalopathy, the progressive degenerative disease associated with repetitive mild traumatic brain injury at the root of a billion-dollar concussion settlement soon to be disbursed by the NFL.

While the active varsity athletes in this study did not report or show signs of significant health problems, scientists are concerned about what long-term effects may emerge from these changes in brain structure and operations. Previous research has found that professional football players have an elevated risk for depression, cognitive impairments, earlier onset of Alzheimer’s disease, and memory problems.

Although there are links between concussions, brain damage, and the link between concussions and CTE, the cause of CTE remains unknown. Researchers are hoping that further investigations into teenage brains might help reveal these causes — and help develop a plan to stop it before it’s too late.

Abstract: There is growing concern about how participation in contact sports affects the brain. Retrospective evidence suggests that contact sports are associated with long-term negative health outcomes. However, much of the research to date has focused on former athletes with significant health problems. Less is known about the health of current athletes in contact and collision sports who have not reported significant medical issues. In this cross-sectional study, advanced magnetic resonance imaging (MRI) was used to evaluate multiple aspects of brain physiology in three groups of athletes participating in non-contact sports (N = 20), contact sports (N = 22), and collision sports (N = 23). Diffusion tensor imaging was used to assess white matter microstructure based on measures of fractional anisotropy (FA) and mean diffusivity (MD); resting-state functional MRI was used to evaluate global functional connectivity; single-voxel spectroscopy was used to compare ratios of neural metabolites, including N-acetyl aspartate (NAA), creatine (Cr), choline, and myo-inositol. Multivariate analysis revealed structural, functional, and metabolic measures that reliably differentiated between sport groups. The collision group had significantly elevated FA and reduced MD in white matter, compared to both contact and non-contact groups. In contrast, the collision group showed significant reductions in functional connectivity and the NAA/Cr metabolite ratio, relative to only the non-contact group, while the contact group overlapped with both non-contact and collision groups. For brain regions associated with contact sport participation, athletes with a history of concussion also showed greater alterations in FA and functional connectivity, indicating a potential cumulative effect of both contact exposure and concussion history on brain physiology. These findings indicate persistent differences in brain physiology for athletes participating in contact and collision sports, which should be considered in future studies of concussion and subconcussive impacts.