Chronic traumatic encephalopathy (CTE) is a type of brain damage that has been found in 345 of 376 deceased former National Football League (NFL) players, according to a 2023 report by the Boston University CTE Center, which has led the effort to diagnose CTE cases. In comparison, a 2018 BU study of the general population found one CTE case in 164 autopsies, and that one person with CTE had played college football.[1] The NFL acknowledged a link between playing American football and being diagnosed with CTE in 2016, after denying such a link for over a decade and arguing that players' symptoms had other causes.[2]
While much attention in the NFL has focused on limiting or treating concussions, the latest medical research indicates that the brain damage in CTE is caused by the cumulative impact of all collisions involving a player's head,[3][4] which confirms what was generally known nearly a century ago but was then largely forgotten.[5] The NFL has implemented rule changes to reduce collisions to the head[6] and has sought to improve helmet design.[7] Critics respond that significant head trauma is inevitable for bigger, faster players in tackle football[8] and that helmets are of limited use in preventing a player's brain from crashing into their skull, which is the cause of the brain damage that leads to CTE.[9]
As more parents (including some NFL players) decide not to let their children play football,[10][11] it remains to be seen whether football will eventually face a significant decline in popularity[12] like boxing, which fell from prominence as the brain damage suffered by ex-boxers drew more public attention.[13] Football is currently the most-watched sport in the U.S. by a substantial margin while basketball is the most-played sport.[14]