When the NFL season kicks off next month, millions of Americans will gather around their televisions to watch athletes of comic book proportions crash into each other at breathtaking speeds. Inevitably, those players’ heads will smash into each other, leaving them dazed on the field. And according to a major new study, these repeated head-on collisions may eventually lead to a degenerative brain disease for many — if not most — of the players long after they’ve left the field. For years now, America has been reckoning with the tension between its love for football and the growing evidence of its dangers. Those concerns can be boiled down to three letters: CTE, or chronic traumatic encephalopathy, which is the progressive brain disease that can lead to dementia, depression, suicide, and other serious mental health problems. One major question over the past 20 years has been: Exactly how often does playing football lead to CTE? What are the risks for peewee players versus pros? How quickly does the brain deteriorate once the disease takes hold? And new research, published this week in the British Medical Journal, has provided us with some staggering answers. After analyzing the death records for hundreds of former NFL players, the co-authors concluded that at least 25 percent of the former players who died between 2016 and 2021 had CTE at the time of their death. And the actual prevalence could be much higher, but more players’ brains would have to be given over to scientists for a CTE assessment for us to know for sure. Because among the 338 players whose brains were donated and studied, the CTE rate was an astonishing 93 percent. The question is, according to the researchers: Is that percentage skewed because the players exhibiting CTE symptoms were more likely to offer up their brain for research? Or, as the authors suggest is possible, is the real CTE rate closer to 90 percent? Only further research will be able to tell us, but even the latest estimate — one in four — is cause for concern. It’s a stark reminder of football’s risks, delivered right on the cusp of a new season for pro, college, and high school teams around the country. And according to the Aspen Institute’s annual State of Play report, there are signs that the game’s future may actually be at risk. More and more American parents are steering their kids away from tackle football. How long can an elite league like the NFL last when the pool of players is getting smaller and smaller — at the same time the scientific evidence of its dangers is becoming clearer and clearer? The youth football pipeline is drying up Despite the latest research, the NFL is going to be fine in the short term. Professional football is the biggest TV show in the country: Last year, 83 of the top 100 rated TV shows were NFL games, up from 72 in 2024. The next Super Bowl will almost certainly attract more than 100 million viewers and end up the single most-watched TV program in the US for the whole year. Football is one thing that transcends politics in an increasingly polarized America. But with each new piece of evidence about the physical and mental costs of playing football, football’s long-term dominance looks less and less certain. Already, if you dig into the trend lines for youth participation, they reveal a real threat to the sport’s future. Let’s start with the good news for football enthusiasts: Flag football has become more and more popular among kids, supported by investments and promotion by the NFL itself and expert consensus that it’s much safer than tackle, especially when it comes to head injuries. According to the Aspen Institute’s State of Play survey, flag football participation among kids ages 6 to 12 grew by 13.6 percent from 2019 to 2024, while tackle football play dropped 7 percent among the same age group over that time. But it’s participation among the next age group that may be most revealing. According to the Aspen Institute, tackle football participation rates among Americans ages 13 to 17 — the prime age for middle school and high school teams — decreased 9 percent from 2019 to 2024. It has even fallen behind tennis among the teenage cohort. Many of the tweens who play flag football may never strap on a helmet to play tackle. Even if fewer kids play tackle football year over year, the sport may still subsist on its promises of upward mobility for people who come from poorer backgrounds. With the recent introduction of compensation for college players, elite athletes can make millions of dollars in income before they even reach the NFL. It may be no surprise, then, that the young people still playing tackle football are more likely to be lower-income and live in conservative states. Another study found that Black and Hispanic parents, who on average earn less money than their white counterparts, are more likely to see football as a path to college scholarship or even a professional career; the Washington Post reported in 2023 that the proportion of white players at the college level is falling while the percentage of Black players is rising. Football players are often thought of as modern gladiators: participants disproportionately from lower classes aspiring to riches and glory in a violent game for the viewing pleasure of the general public. That’s becoming more and more true as we learn more about its dangers. As the annual hoopla around the NFL kickoff makes clear, football’s cultural dominance remains unrivaled among professional sports. But this new study has left even me, a lifelong football fan, wondering how much longer it can, and should, last.