NFL players are four times more likely than the general population to die of neurodegenerative diseases such as dementia and Parkinson's, according to a study released Wednesday by Mass General Brigham, Boston University and the Concussion & CTE Foundation.
The researchers studied 19,824 athletes who played in the NFL between 1960 and 2019, including the 1,994 who have died, calling it the "biggest retrospective cohort study to date." They found the rate of neurodegenerative death was "more significant" for younger players: Those who died before age 60 had 12-fold higher rates of neurodegenerative death than the general population, according to the study.
The results are "tragic but not surprising," co-senior author Dr. Daniel Daneshvar, chair of physical medicine and rehabilitation at Mass General Brigham and Harvard Medical School, said in an interview Thursday with ESPN.
"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," he said in a statement about the study.
A spokesman for the NFL did not immediately respond to a request for comment.
Researchers expected this result when they asked the Centers for Disease Control and Prevention for death certificates of the players who had died, Daneshvar said. Here's what surprised them: Skill-position players had a neurodegenerative disease listed as a cause of death at nearly twice the rate of offensive and defensive linemen, "potentially related to greater cumulative g-force exposure, which [has] been associated with higher [neurodegenerative disease] risk," according to the study.
Still, NFL players had lower death rates from other diseases than national averages. They were less likely to die from cancer, cardiovascular disease and suicide because the NFL population is "generally healthier," the researchers said in the statement.
"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," Daneshvar said. "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 [chronic traumatic encephalopathy]."