We are talking about athletes who have participated in at least one NFL game during their careers. Approximately 25% of them had CTE at the time of their death — a degenerative brain disease that is associated, among other things, with multiple head injuries. "We know that this pathological process can partly be caused by repeated brain injuries. But we did not know how widespread the disease is," quotes NPR the lead author of the study, Dr. Daniel Daneshvar. The link between professional American football and CTE has been discussed for many years, but determining the actual prevalence of the disease is difficult. CTE can only be reliably diagnosed after death by examining brain tissue. Therefore, a significant portion of the scientific data has been obtained by studying the brains of deceased athletes, which were donated to researchers by their families. Often, these are former players who exhibited possible signs of the disease during their lifetime, particularly memory loss or significant mood swings. Because of this, such samples do not allow for a direct determination of the prevalence of CTE among all professional football players. The authors of the new study used the UNITE brain bank collection at Boston University. It contains brain samples from more than 330 NFL players who died between 2008 and 2021. CTE was found in 93% of them. To assess the prevalence of the disease, the researchers focused on the period from 2016 to 2021, when the proportion of deceased players whose brains were donated for research was the highest. According to Daneshvar, the estimated 25% is a "lower bound," and the actual proportion of former NFL players with CTE may be higher. A separate survey showed that about one-third of former players from the 32 NFL teams believe they may have CTE. However, it is currently impossible to confirm such a diagnosis during their lifetime. The disease is associated not only with American football. An increased risk is noted among people who have regularly suffered head injuries, including military veterans and high-level athletes engaged in contact sports. A recent study of hockey players also found a link between the length of a sports career and the risk of developing CTE. The authors of the study separately examined the link between CTE and dementia. A high correlation was found between dementia during life and the identification of the most severe, fourth stage of CTE after death. The NFL told NPR that the league continues to work on improving the safety of American football, including taking measures to reduce the number of concussions and head impacts. Some professional players have also begun using soft protective padding in helmets designed to further cushion strong blows. At the same time, degenerative brain diseases also occur in people who have never suffered such injuries. According to a study published in Nature Medicine, among Americans over 55 years old, the risk of developing some form of dementia during the remainder of their life is estimated at 42%.
