A Boston University-led study estimates that nearly three-quarters of former NFL players who died between 2008 and 2023 had chronic traumatic encephalopathy (CTE). Club owners make money from a spectacle built through players’ strength, skill and endurance. Researchers are examining what remains in those players’ brains after the playing careers have ended.
Published in JAMA Network Open, the study involved researchers from Boston University, Mass General Brigham and the Concussion & CTE Foundation. CTE is a neurodegenerative disease diagnosed in people with substantial exposure to repeated head impacts. Doctors can only definitively diagnose it after death.
The researchers found some degree of CTE pathology in 362 of the 387 donated brains they examined: approximately 94 percent. But families were much more likely to donate the brains of former players who’d experienced cognitive symptoms. Simply applying that figure to every deceased player would overlook this selection bias.
To address it, the researchers used National Death Index records and examined factors including cognitive symptoms, age at death, playing position and years in the NFL. They estimated that families of players with cognitive symptoms were about five times more likely to donate their brains. After adjusting for this difference, they estimated a prevalence of 74.5 percent across the full group of 2,362 former players who died during the period, including those whose brains weren’t donated.
The scale is appalling. Researchers have found CTE in fewer than 1 percent of thousands of donors to community brain banks in the United States, Australia, Austria and Brazil. The research team also cites previous studies showing that NFL players develop dementia at four times the rate of the general population.
These are workers whose job exposes them to repeated blows to the head. Their employers sell the resulting matches as entertainment. The wage contract joins the two activities: owners employ players to produce something they can sell, and players perform the physical labour from which those owners profit. The damage can accumulate in the course of doing the job.
The consequences don’t obey the dates on a playing contract either. A player’s employment can end years before he develops serious difficulties with memory, reasoning or everyday tasks. If he loses the ability to live independently, relatives and carers face needs that extend far beyond his former workplace. Employers buy labour power for a particular period; workers have to live in the bodies they’ve worked with for the rest of their lives.
“It’s hard to learn what the guys who built the game have suffered through,” said Matt Hasselbeck, an 18-year NFL veteran and ambassador for the DIAGNOSE CTE study. “I’m looking at this like getting a scouting report. Now that we know what we’re up against, we have a better chance of winning. I can’t take back the hits I took, but I can sign up for research and do whatever I can to help the scientists so they can find a cure in my lifetime. We have to learn from this data to make the game safer, because we can’t accept these numbers for the next generation of players.”
Former players and their families have helped researchers establish the extent of the damage by participating in studies and donating brains. Researchers hope to develop a diagnosis during life and effective treatments. Senior author Yorghos Tripodis says discoveries from the brain bank have already brought researchers substantially closer to diagnosing CTE during life.
Owners can replace players who can no longer perform and keep selling matches. They don’t have to restore a retired player’s health before fielding his replacement. They can report a profitable season while former employees and their families struggle with damage accumulated on the job.
An owner can eventually sell the club and leave the sport. A former player whose memory and independence are deteriorating has no equivalent exit.
