At least one in four former NFL players who died between 2016 and 2021 had chronic traumatic encephalopathy (CTE) [1].
The findings highlight the severe long-term brain health risks associated with repeated head trauma in professional football. Because CTE can only be definitively diagnosed after death, the data provides a critical window into the neurological toll of the sport.
The study was released Tuesday, Aug. 25, 2026 [2]. It was conducted by researchers from Mass General Brigham, Boston University, and the Concussion & CTE Foundation in Boston, Massachusetts.
Chronic traumatic encephalopathy is a degenerative brain disease found in people with a history of repetitive brain trauma. The research specifically examined the prevalence of the disease among deceased athletes to determine how common the condition is within the NFL population.
According to the report, at least 25% [1] of the former players in the study group were found to have the disease at the time of death. This figure underscores the prevalence of the condition among those who played in the league during the specified timeframe.
Dr. Robert C. Cantu, a founding member and medical director of the Concussion & CTE Foundation, was among the leaders involved in the research. The collaboration between the Boston-based medical institutions aimed to provide a clearer understanding of the link between football-related impacts and permanent brain damage.
The research focused on the period from 2016 to 2021 to establish a contemporary baseline for the disease. By analyzing brain tissue from deceased players, the team sought to quantify the risk that repeated concussions and sub-concussive hits pose to professional athletes.
“At least one in four former NFL players who died between 2016 and 2021 had CTE.”
This data suggests that brain degeneration is a significant risk for a substantial portion of former professional football players. By quantifying the prevalence of CTE in a specific cohort, the study provides a scientific basis for ongoing debates regarding player safety, concussion protocols, and the long-term liability of sports leagues regarding neurological health.
