For a football player, a collision can last less than a second. The consequences, however, may become visible decades later, when the roar of the stadium has disappeared and the athlete is long retired.
That possibility is at the centre of a new study published in the BMJ in August 2026, which examined deaths among former NFL players and found an extraordinarily wide range of possible chronic traumatic encephalopathy (CTE) prevalence. The researchers identified CTE in 315 of 338 former NFL players whose brains had been donated for examination. Depending on how the researchers account for the players who did not donate their brains, the estimated prevalence among players who died between 2008 and 2021 ranged from 18.5% to 98.7%.
