1 in 4 former NFL players who died 2016-2021 had CTE, study finds

A new study published in The BMJ estimates that at least 1 in 4 former NFL players who died between 2016 and 2021 had chronic traumatic encephalopathy (CTE), a neurodegenerative disease linked to repeated head impacts. The research, led by Mass General Brigham, Boston University, and the Concussion & CTE Foundation, analyzed 1,712 former players who died from 2008 to 2021, using death certificate data and brain donations to correct for selection bias in earlier studies Source: CNN.

Key findings

• Among 338 brain donors, 93% were diagnosed with CTE, including 31% with severe stage IV CTE Source: Gizmodo.
• Nearly 60% of donors met criteria for dementia, with higher odds in those with stage IV CTE Source: Gizmodo.
• The study's minimum estimate for CTE prevalence among all former players who died 2016–2021 is 24.5%, up from 18% for the 2008–2021 period Source: Ground News.

Context and reaction

Previous research found CTE in 99% of donated brains, but that was criticized for selection bias because families may have donated due to observed symptoms. This new study attempts to overcome that by comparing total deaths to confirmed CTE cases Source: CNN. An NFL spokesperson said the league is committed to reducing head impacts and providing resources for player health Source: CNN. Lead author Dr. Daniel Daneshvar noted that most head impacts occur at the college, high school, and youth levels, not just in the NFL Source: CNN.

Experts caution that CTE can only be diagnosed post-mortem, and the true prevalence may be higher than the conservative estimates Source: Gizmodo.