Researchers from Mass General Brigham, Boston University and the Concussion & CTE Foundation released a study in the BMJ estimating that one in four former National Football League players who died between 2016 and 2021 had chronic traumatic encephalopathy (CTE). The analysis, described by the journal as one of the most informative estimates of CTE burden among former NFL athletes, used death‑certificate data to compare the total number of NFL deaths with the number of brain donors confirmed to have CTE.
Methodology and Findings
Between 2016 and 2021, 878 former NFL players died. Of those, 235 families donated the players’ brains for research, and 215 of the donated brains were diagnosed with CTE. The study notes that prior research, which found CTE in 99% of brain donors, may have been biased because it relied on a self‑selected group of families who observed symptoms before donation.
CTE is a neurodegenerative disease linked to repeated blows to the head. It can only be confirmed after death, but symptoms often include memory loss, impulse‑control problems, anxiety, depression and anger. While the disease is most commonly associated with contact sports such as football, hockey and soccer, it has also been identified in the brains of soldiers exposed to explosions and in individuals who suffered domestic violence.
Implications for Player Safety
Lead author Dr. Daniel Daneshvar, chair of physical medicine and rehabilitation at Mass General Brigham and associate professor at Harvard Medical School, emphasized that repeated traumatic brain injuries raise the risk of neurodegenerative disease. He noted that former NFL players die from neurodegenerative disease at roughly four times the rate of the general population.
Daneshvar stressed that the majority of head impacts occur before the professional level. “The bulk of the head impacts that these former NFL players experienced didn’t occur at the NFL level. They occurred at the collegiate level, high school level and often at the youth level,” he said. He urged that reducing contact practices across all levels—college, high school and youth—could substantially lower cumulative head‑impact burden.
League Response and Policy Context
The NFL reiterated its commitment to player safety, citing ongoing efforts to limit concussions and head impacts. The league’s 2011 Collective Bargaining Agreement reduced the number of contact practices during the season, and the current agreement, ratified in 2020, continues those restrictions through 2031. The Ivy League banned full‑contact tackling during practices five years later, and the Supreme Court cleared the way for the NFL’s 2016 settlement of concussion‑related lawsuits with retired players.
Daneshvar concluded, “If the changes that have been implemented at the NFL level, including reducing the amount of contact in sports practices to less than one per week, were propagated at the collegiate, high school, and youth levels, athletes would be better off.” He encouraged current and former athletes experiencing cognitive symptoms to seek evaluation by a neurodegenerative disease specialist.
Original reporting: KTBS 3 (Shreveport) — read the source article.
