New Research Estimates 75 Percent of Deceased NFL Players Had CTE

High CTE Rate Found in Former Players

A new study estimates that roughly 75 percent of former NFL players who died between 2008 and 2023 had chronic traumatic encephalopathy. The brain condition, commonly called CTE, is linked to repeated hits to the head in contact sports.

The findings were published in JAMA Network Open by researchers from Boston University, Mass General Brigham, and the Concussion and CTE Foundation. The authors described the paper as the first broad effort to examine the prevalence of the disease across deceased players. A previous paper by some of the same authors estimated that one in four former players who died between 2016 and 2021 had CTE.

Study Setup and Limitations

CTE can only be diagnosed after a person dies, and scientists are still searching for a way to test for it during life. Past studies faced questions about selection bias because they relied on families donating the brains of players who already showed symptoms.

To address that issue, this project examined 2,362 cases. Researchers combined records from 396 players who donated their brains with data from 1,966 deceased players who did not. Nearly 94 percent of the donated brains had CTE. The donors were more likely to be white, die at a younger age, and spend more years in the league than non donors. Even after adjusting for those factors, the authors reported that the rate of CTE among deceased players remains high.

The researchers noted several limits to the work. The data only applies to deceased players and cannot predict disease rates for living players. The study also did not look at college or high school players, where a lack of data makes research difficult. In addition, the findings do not show which symptoms players suffered. CTE has four stages, and players in the earliest stages may die without showing symptoms.

Responses to the Findings

Julia Gallini, the lead author of the paper, stated that the estimated rate was concerning. She pointed out that more work must be done to support families, create tests for the living, and treat symptoms connected to the disease.

The NFL said in a statement that the league continuously works to make football safer by using plans to cut down on concussions and head contact. League officials urged former players to use medical resources if they have health concerns. The NFL Players Association said these studies help people understand the long term effects of playing football.