Study Finds 75 Percent of Ex-NFL Players Who Died Had CTE
Left 20%
Center 60%
Right 20%
1 left · 3 center · 1 right
What happened
Researchers at Boston University, the Concussion & CTE Foundation, and Mass General Brigham published a study in JAMA Network Open estimating that nearly 75 percent of former NFL players who died from 2008 to 2023 had chronic traumatic encephalopathy (CTE), a degenerative brain disease associated with repeated head impacts that can be diagnosed only after death. Of 387 donated brains, 94 percent showed some form of CTE; after estimating that families of players with cognitive symptoms were five times more likely to donate, the authors adjusted the rate to 74.5 percent among roughly 2,360 deceased former players—narrower than an August estimate from some of the same researchers of 25 to 98 percent among players who died from 2016 to 2021. They also estimated that about 27 percent of the deceased players had dementia, and noted CTE in under 1 percent of community brain-bank donations. The NFL said it “continuously strives to make the game of football safer” through equipment such as Guardian Caps and rule changes, and the NFL Players Association called such studies “critical” to understanding football’s long-term health impacts. The authors cautioned that the estimate applies only to deceased players and does not predict CTE among living former or active players.
Sourcing check · Fully on the record · 5 articles
5 of 5 articles cite a named source for the story. It was on the record from the first report.
What these terms mean and how they're counted
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- On the record means the article cites a source by name for the story's main claim: a person, or an institution speaking officially, such as a company statement or a named agency's spokesperson. The opposite is an unnamed source. The count is how many of the counted articles cite at least one such source; the names are everyone named across them, each once however the articles spell it. Here: Yorghos Tripodis, NFL, Boston University researchers, Julia Gallini, Matt Hasselbeck and researchers at the Concussion & CTE Foundation, Boston University and Mass General Brigham
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This is about who is cited, not whether the story is true. Each source below says what it names. How we count
Omitted — what each side leaves out
Unpacked
Left-leaning coverage presents the headline result as a count of illness, not just of brain lesions. It reports an estimate that 27% of the dead players had dementia. Right-leaning coverage never gives a dementia figure, quoting instead the paper's line, "Many cases may have been early stage at the time of death and possibly symptom free." That split decides whether a reader sees a wave of disease or a pathology finding that often came with no symptoms.
Left-leaning coverage leads by calling the result the highest estimation to date and three times an earlier figure. Right-leaning coverage instead dwells on limits: the estimate does not apply to players who are still alive, and it does not address college or youth football.
Of the estimated CTE cases, how many were advanced disease and how many were a handful of lesions that may never have caused symptoms?
Bottom line
NBC News hung a 27 percent dementia estimate on the CTE study. The Daily Caller never printed that figure and left readers with the paper's warning that many cases may have produced no symptoms.
The receipts — 4 facts one side's coverage lacks
- The paper said many CTE cases may have been early stage at death and possibly symptom free
- Families of players with cognitive decline were about five times likelier to donate brains
- Only about 1% of brains donated to banks in the U.S., Austria and Brazil have signs of CTE
- CTE is classified in stages I-IV, and symptoms often do not show in the earlier stages
The Left View
NBC News framed the result as “the highest estimation to date” and three times an August figure of one-quarter of players who died over five years, and explained how repeated head jolts can cause tau proteins to accrue in brain regions that regulate behavior and emotion. Study leader Yorghos Tripodis told NBC he “had to double-check the numbers,” while the outlet noted that not everyone with CTE signs develops symptoms and quoted him saying dementia in this group is “very likely” from CTE. NBC recounted criticism that earlier brain-bank samples were biased—citing a prior Boston University finding of CTE in 99 percent of donated former-NFL brains—and presented the new correction as an effort at a more accurate rate. Experts it cited treated the results as underscoring in-life diagnosis and prevention; Tripodis said that reducing brain impacts “substantially decrease[s] the risk.”
The Right View
The Daily Caller described the paper as “the first comprehensive effort” to gauge CTE among deceased former NFL players and foregrounded the authors’ caveats: the estimate “applies just to dead NFL players and doesn’t make a prediction regarding living players,” does not address college or youth football, and “doesn’t provide any information of what, if any, symptoms came about.” It highlighted the researchers’ statement that “Many cases may have been early stage at the time of death and possibly symptom free,” noting that CTE is staged I–IV and that symptoms often do not appear in earlier stages.
Our Take (balanced)
Left-leaning coverage’s strongest argument is that even after a fivefold donation-bias correction, estimated CTE in this deceased NFL cohort still far exceeds the under-1-percent rate in community brain banks, and the authors tied a 27 percent dementia estimate in that group to CTE. Right-leaning coverage’s strongest argument is the study’s own limits: it covers only players who have already died, many of whom may have had early-stage, possibly asymptomatic disease, and it “doesn’t make a prediction regarding living players.” The central unresolved tension is whether a high, bias-adjusted CTE rate in a historical deceased cohort is evidence of a pervasive football-related brain-disease problem or a finding too bounded by autopsy selection, playing era, and silent cases to describe the sport as it is played now.
5 sources
- Study estimates 75% of NFL players who died over 15-year span had CTE
- Study Reveals Estimated 75% Of NFL Players Who Died From 2008-2023 Had CTE
- Nearly 75% of ex-NFL players who died from 2008-2023 had CTE, study finds
- Study estimates 75% of NFL players who died in recent years had signs of CTE
- Experts react to new findings on CTE in former NFL players
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