A multi-institution study of former NFL players analyzed medical records and brain donations to assess how common chronic traumatic encephalopathy (CTE) and dementia are among players.

Among 1,712 deceased former players studied from 2008 to 2021, including 338 who donated brains, 93% of donors had CTE and 31% had severe stage IV CTE, with nearly 60% showing dementia.

In a subset of brains from 878 players examined between 2016 and 2021, 235 donated brains were studied and 215 showed CTE.

The findings reinforce concerns about neurological risks in football and support reforms in helmet design, concussion protocols, and rule changes to reduce head impacts.

Experts urged athletes with cognitive symptoms to seek evaluation from neurodegenerative disease specialists and emphasized reducing head impact burden across youth, high school, college, and professional levels.

The study notes most head impacts occurred at collegiate, high school, and youth levels, suggesting early-life exposure contributes to long-term risk.

Researchers caution that more prospective, long-term studies are needed to clarify the link between CTE and dementia and to assess how reforms may reduce risk across eras and play levels.

Dementia was common among brain donors, underscoring the need for prevention by reducing repetitive head impacts across all levels of football, not only the NFL.

CTE is a degenerative brain disease linked to repeated head impacts, with symptoms including attention and memory problems, dementia, mood disorders, and headaches.

The study calls for broad prevention measures targeting all levels of play to limit cumulative head impacts and protect long-term brain health.

Some deaths with dementia were not primarily attributed to neurological disease, indicating possible misclassification of cause of death in certain cases.

Lead author Daniel Daneshvar noted that NFL players have about a fourfold higher death rate from neurodegenerative disease compared to the general population.