Study links contact sports to brain injuries, dementia

Boston — A recent study of former athletes who participated in contact sports shows that more than 7 out of 10 experienced significant brain injuries over their lifetime, and almost as many endured dementia before dying.

The Boston University study involved 75 athletes who donated their brains to science. All but eight played football, while the rest participated in other contact sports such as boxing or soccer. The football players, of whom 16 played professionally and 11 semiprofessionally, played the game for an average of 12 years.

All of the athletes underwent brain scans while they were alive and were an average age of 62 at the time. The group’s average age at death was 67.

The scans showed indications of injury to the brain’s white matter, also known as white matter hyperintensities. The scans were then compared with brain autopsies, which “showed that white matter hyperintensities were associated with neuropathological changes,” an American Academy of Neurology press release states.

Those white matter injuries were more common the longer an athlete played a contact sport or the more head impacts they endured during their careers.

Nearly two-thirds of the athletes (64%) had dementia before their deaths. Their autopsies determined that 71% had chronic traumatic encephalopathy – a neurodegenerative disease associated with repeated blows to the head.

“Our results are exciting because they show that white matter hyperintensities might capture long-term harm to the brain in people who have a history of repetitive head impacts,” study author Michael Alosco, an associate professor of neurology at the BU School of Medicine, said in the release. “White matter hyperintensities on MRIs may indeed be an effective tool to study the effects of repetitive head impacts on the brain’s white matter while the athlete is still alive.”

The study was published online Nov. 24 in Neurology, the medical journal of the AAN.