Former NFL players are four times more likely than the general population to die from neurodegenerative diseases like dementia and Parkinson's disease, according to a study released Wednesday. Mass General Brigham, Boston University and the Concussion & CTE Foundation conducted the research.
The study examined 19,824 athletes who played in the NFL between 1960 and 2019, including 1,994 who have died. Researchers described it as the largest retrospective cohort study of its kind to date.
Players who died before age 60 showed a 12-fold higher rate of neurodegenerative death compared to the general population. Skill-position players had nearly double the rate of offensive and defensive linemen, a gap researchers tied to greater cumulative g-force exposure.
"This is the clearest population-level evidence we have ever had that NFL players are dying due to neurodegenerative disease at real and measurably higher rates," said Dr. Daniel Daneshvar, co-senior author of the study and chair of Physical Medicine and Rehabilitation at Mass General Brigham and Harvard Medical School.
Despite the elevated neurodegenerative death rates, NFL players had lower rates of death from cancer, cardiovascular disease and suicide than national averages. Researchers said the finding pointed toward a different explanation than lifestyle factors.
"One of the things that has been thought to be a reason that some NFL players have higher rates of dementia is that they're so big, and they have such poor eating habits, they have increased rates of heart issues and blood vessel issues, more sleep apnea, which can increase dementia rate," said Daneshvar. "But what we found is they're actually dying from these other things at a lower rate than the general population. So the most likely explanation for this elevated rate of neurodegenerative disease in NFL players is CTE."
Researchers noted that death certificates often understate neurodegenerative causes, meaning the true rate could be even higher. The study found consistent results across different NFL eras despite rule and equipment changes.
"The research suggests that the most effective way to decrease someone's risk of neurodegenerative disease is to decrease the total amount of force to the head they've experienced, by changing when they start playing contact sports, by changing the way they practice," said Daneshvar.
The findings echo a 2025 ESPN and KFF survey of 546 men from the 1988 NFL season, in which 15% reported a dementia diagnosis. That compares to under 4% of American men 65 and older nationally.