Ice hockey is fast, intense, and thrilling—and often hard-hitting. That means hockey players risk chronic traumatic encephalopathy (CTE), a neurodegenerative disease linked to repetitive head impacts. CTE is most closely associated with football, but in theory could happen in any contact sport. A new study has established a clear connection between years of ice hockey play and CTE. Harvard Public Health spoke with Jesse Mez, co-director of clinical research at Boston University’s CTE Center and the study’s coauthor.
Why study this topic?
Boston University has a brain bank for participants exposed to repetitive head impacts. The vast majority of donors have been American football players, but we’ve also collected brains from ice hockey players, rugby players, and others. While we saw a clear dose-response relationship (more exposure increases health consequences) in football players, it was only recently that we had enough data to analyze ice hockey. This study is crucial to understanding how risks apply across different sports.
What did you find?
What surprised me was how strong the relationship was. The odds of developing CTE increased by about 34 percent for each additional year of play. We also saw significant links between years of play and tau protein accumulation in the brain, which correlated with dementia and impaired daily function. While enforcers—players who fight more often—had higher risks, the overall takeaway is that years of play are the primary driver of CTE risk.
What would you like to see happen based on the study’s results?
I want people to understand that it’s not just about symptomatic concussions, it’s the accumulation of thousands of impacts over a career that increases risk. Policies that reduce impacts can make a big difference. I hope this study helps players and their families make informed decisions about their health while encouraging safer ways to play the sport.
—Paul Adepoju
(Study in JAMA Network Open, December 2024)