Study points to striking rates of brain disease in NFL players

Nearly 75% of the NFL players who died between 2008 and 2023 likely had CTE, a rate that alarmed researchers since less than 1% of donors to community brain banks have the disease.(CN) — Nearly three out of four former NFL players who died between 2008 and 2023 may have had a brain disease linked to repeated head injuries, researchers estimate.The study, published Wednesday in JAMA Network Open, details how researchers believe 74.5% of the 2,362 former NFL players who died during that period had chronic traumatic encephalopathy, or CTE, a degenerative brain disease associated with repeated blows to the head.CTE can affect memory, thinking and behavior, although not everyone with the disease develops symptoms. It can only be definitively diagnosed after death.Researchers at Boston University, Mass General Brigham and the Concussion & CTE Foundation took into account that families who suspect a loved one had CTE are more likely to donate their brain for research.Of the 387 deceased NFL players whose brains were examined, 362, or 94%, had CTE. That number could be misleading, though, since families who donate brains aren’t necessarily representative of all former players.To get a more accurate estimate, researchers looked at death records for all 2,362 former NFL players who died during that period. They also considered factors such as cognitive symptoms, age at death, playing position and years spent in the NFL.Their analysis suggested that families of players who experienced cognitive symptoms were about five times more likely to donate their brains than families of players without those symptoms.After adjusting for that difference, the estimated prevalence dropped from 94% to 74.5%.“CTE is found in less than 1% of donors to community brain banks, so a number this high is striking,” said Yorghos Tripodis, professor of biostatistics at Boston University School of Public Health and the study’s senior author, in an email.Their findings build on an earlier study from the same research group that estimated CTE prevalence among deceased NFL players could range anywhere from 25% to 98%.The new analysis narrows that uncertainty by examining differences between players whose brains were donated and those whose brains were not.Tripodis cautioned against confusing the presence of CTE with symptoms of the disease.“Disease in the brain and symptoms during life are different things, and our estimate applies only to players after death,” he said.Previous research has also found that former NFL players develop dementia at roughly four times the rate of the general population, according to the researchers.Although CTE cannot yet be definitively diagnosed in living people, scientists are studying biological markers that could eventually make earlier detection possible.One effort, called DIAGNOSE CTE, follows former college and professional players to look for biological signs of the disease.“A reliable diagnosis during life would let us start clinical trials for treatments,” Tripodis said.Preventing the disease is another priority, particularly by limiting the number of blows to the head that football players experience. Advocates call for solutions such as no-contact practices and delaying tackling until high school.“Repetitive head impacts are the only known risk factor for CTE, which makes it a preventable disease,” Tripodis said. “Reducing the number of hits to the head should be a priority at every level of the game.”Tripodis also wants former players and their families to know that medical support is available, even as researchers continue looking for treatments.“Help is available and there is reason for hope,” Tripodis said. “Many players with CTE in their brain never develop severe symptoms.”Subscribe to our free newslettersOur weekly newsletter Closing Arguments offers the latest about ongoing trials, major litigation and rulings in courthouses around the U.S. and the world, while the monthly Under the Lights dishes the legal dirt from Hollywood, sports, Big Tech and the arts.Additional Reads