Almost every former National Football League player who died between 2016 and 2021 and allowed their brains to be evaluated were found to have chronic traumatic encephalopathy, stark evidence of the toll repeated head impacts can take on athletes.
Researchers obtained personal information and causes of death for 878 players who died during the five-year period, when brain donations were highest. Of the 235 athletes whose brains were subject to the postmortem neurological examination, 215 had confirmed CTE, according to findings published Tuesday in the British Medical Journal.
CTE, a progressive brain disease tied to repeated head trauma that’s common in contact sports like football and boxing, can only be definitively diagnosed by examining the brain after death. When the researchers included all the football players who died in their analysis, they determined a “conservative minimum” of nearly 25% had CTE.
The findings are “a wake-up call for the NFL and scientific communities,” said lead author Daniel Daneshvar, chair of physical medicine and rehabilitation at Mass General Brigham. Previous brain bank studies involving regular people living in a community detected CTE in fewer than 1% of the population.
The magnitude of the issue remains underappreciated, even as awareness of the condition has soared in recent years.
In the study, donors with advanced stages of CTE frequently suffered from dementia, with the most severe patients showing substantial cognitive decline and impairment in daily function. Still, only 41% of those who were diagnosed with dementia before their deaths from 2008 to 2021 had neurodegenerative disease listed as a primary or secondary cause, the researchers found.
“This study is a sobering reminder that football carries real risks, and those risks can have lasting consequences for players and their families,” said Brandon Parker, a spokesman for the NFL Players Association. “The findings should serve as a call to action across the entire football ecosystem.”
The National Football League said it’s committed to making sure the community has access to resources to support physical and mental wellbeing.
“The NFL continuously strives to make the game of football safer, including by implementing strategies to reduce concussions and head impacts,” an NFL spokesperson said in a statement.
Mike Webster, a Hall of Fame center for the Pittsburgh Steelers, was the first former NFL player found to have CTE after his death in 2002. Since then, doctors have diagnosed hundreds of others with the disease, including several who died by suicide.
The NFL settled a lawsuit in 2013 brought by more than 5,000 retired players who claimed the league had failed to share what it knew about the long-term effects of head trauma. The league promised to pay at least $675 million to former players and to set aside $90 million for medical monitoring and research.
It didn’t publicly acknowledge a link between CTE and playing football until 2016.
Top Photo: A helmet on the field at M&T Bank Stadium in Baltimore. Photographer: Rob Carr/Getty Images
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Facts Only
* Former NFL players who died between 2016 and 2021 with evaluated brains showed chronic traumatic encephalopathy (CTE).
* Researchers obtained data for 878 players who died during the five-year period when brain donations were highest.
* Of 235 athletes whose brains were examined, 215 had confirmed CTE.
* A "conservative minimum" of nearly 25% of the analyzed football players had CTE.
* CTE is a progressive brain disease linked to repeated head trauma in contact sports.
* Donors with advanced CTE stages frequently suffered from dementia.
* Only 41% of those diagnosed with dementia before their deaths (2008–2021) had neurodegenerative disease as a primary or secondary cause.
* The NFL settled a lawsuit in 2013 involving claims about head trauma effects.
* The NFL acknowledged a link between CTE and football in 2016.
Executive Summary
Full Take
The narrative presents a stark quantification of a known risk, framing the issue as a systemic failure that requires immediate corrective action from multiple stakeholders. The transition from anecdotal observation to statistical correlation—demonstrating nearly a quarter of the cohort having CTE—serves to establish the severity and broad reach of head trauma risks in contact sports. The shift in focus from diagnosing the disease itself (CTE) to tracking subsequent cognitive decline (dementia) highlights an important public health gap: while brain damage is recognized posthumously, the correlation with long-term functional deficits remains statistically complex across living populations.
The pattern reveals a tension between institutional accountability and scientific latency. The NFL's response involves commitments to safety improvements and financial settlements, which represents reactive governance rather than proactive prevention based on the initial findings. This dynamic suggests that acknowledgment of risk often precedes comprehensive, immediate structural change. Furthermore, the focus on dementia outcomes—where only 41% of dementia diagnoses correlated with neurodegeneration—introduces necessary nuance, suggesting that while exposure to head trauma is a significant factor, other environmental and genetic variables heavily mediate the progression into severe cognitive decline. The implication for agency lies in demanding that future safety protocols move beyond damage mitigation to establishing proactive neurological stewardship for athletes and their families, ensuring that acknowledgement translates into mandatory, sustained responsibility rather than episodic litigation management.
Bridge Questions: If nearly 25% of players carry CTE, what specific, measurable neurobiological markers can be used to mandate immediate preventative changes on the field? How should legal frameworks evolve to assign liability when long-term neurological damage is established posthumously but manifested over decades? What strategies are needed to ensure that acknowledging risk translates into a robust system for familial and player support against resulting cognitive burdens?