The brains of 99 percent of former National Football League players studied showed signs of a disease linked to repeated hits to the head that can lead to aggression and dementia, according to research published in a medical journal on Tuesday.
The findings were based on the broadest review yet of the brains of former football players for signs of chronic traumatic encephalopathy. The condition, also known as CTE, is linked to the sort of head-to-head hits that were long a part of the sport, although the NFL and school leagues have been tweaking the game in recent years to limit blows to the head.
“The data suggest that there is very likely a relationship between exposure to football and risk of developing the disease,” said Jesse Mez, a Boston University School of Medicine assistant professor of neurology, who was lead author of the study published in the Journal of the American Medical Association.
The researchers studied the brains of 202 former athletes who had played football in the NFL, the Canadian Football League or at the college or high school level and found signs of CTE in the brains of 110 of the former 111 NFL players.