New Study Estimates CTE Affects 75% of Former NFLers
Researchers estimate that 74.5% of deceased former players had CTE, providing a clearer look at the condition's prevalence.
Updated on Oct. 28, 2026 in Alzheimer’s
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A new study published in the Journal of the American Medical Association estimates that 74.5% of deceased former NFL players had chronic traumatic encephalopathy (CTE). The research also found that roughly 27.2% of former NFL players experienced dementia during their lifetimes.
Why it matters
Understanding the prevalence of neurodegenerative conditions in contact sports helps clarify the long-term health risks associated with professional football. This study aims to provide a more accurate estimate than previous, smaller reports, aiding in the broader effort to quantify and address player health.
In a study of 2,362 deceased former NFL players, researchers estimated that 74.5% had CTE and 27.2% experienced dementia. While 93.5% of the 396 brain donors examined had CTE, researchers adjusted their analysis to account for selection bias among donor families.
The players
Journal of the American Medical Association
A peer-reviewed medical journal that publishes original research and clinical studies on public health and disease.
Boston University
A research institution where scientists lead major studies on neurodegenerative conditions and brain health.
NFL
The professional football organization that pledged $100 million toward player safety and research initiatives.
The details
CTE is a progressive neurodegenerative condition caused by the buildup of abnormal proteins that damage brain tissue over time. To produce a more accurate estimation, researchers adjusted their data to account for the observation that families who noticed cognitive symptoms in their relatives were five times more likely to donate the brain for study. This statistical adjustment helped reconcile the high prevalence observed in donated samples with the broader, unobserved population of former players.
Timeline
October 28, 2026: Publication of the current study in the Journal of the American Medical Association.
2016-2021: Period during which deceased players died for the study cohort.
September 2016: NFL announced the Play Safe Play Smart initiative.
Health Landscape
This research provides a more rigorous estimate of CTE prevalence than previous, smaller investigations, clarifying the scale of the crisis in professional sports. It updates the context for existing safety measures like the NFL's Play Safe Play Smart initiative.
While this study concerns a specific professional athletic population, it highlights the importance of monitoring cognitive changes in individuals with a history of repetitive head impacts. Concerns regarding memory loss, mood shifts, or executive function should be discussed with a neurologist.
The takeaway
CTE remains a significant health concern for former professional athletes that can only be identified post-mortem. Families of those with a history of head trauma should focus on tracking new cognitive or behavioral changes and consult a healthcare professional about potential warning signs.
Further reading
For more information on neurodegenerative conditions and brain health, explore our Alzheimer’s archive.
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