By most indicators, including TV ratings and attendance at games, football is more popular than ever. Forty-one percent of Americans say football is their favorite sport. But there is a high price being paid by the players providing this entertainment, namely, the risk of chronic traumatic encephalopathy (CTE), a degenerative brain disorder caused by repeated head injuries.
CTE is not about single concussions but the result of smaller, repetitive head impacts that result in lasting structural brain changes which may progress over time. While CTE is strongly associated with tackle football, it has also been linked to ice hockey, rugby, soccer, boxing and wrestling. Symptoms, including memory loss, impaired judgment, poor impulse control, anxiety and depression, may not be noticed until months, years or even decades after the last head trauma. Severe cases have been linked to suicidal behavior and dementia. Widely publicized cases include Baltimore Colts great John Mackey and Aaron Henandez, the NFL star who completed suicide in his jail cell at age 27, and at autopsy was found to have advanced CTE. At present, diagnosis can only be confirmed at autopsy with an examination of brain pathology, and there is no treatment.
In a sample of 202 deceased football players (average age at death 66 years) who were part of a brain donation program at the Boston University CTE center, 87% of all former players and 99% of former NFL players had a neuropathologic diagnosis of CTE. The incidence of CTE in the general population is less than 1%. The severity of CTE pathology was distributed across the highest level of play with all former high school players having mild pathology and most former college and professional players having severe pathology. Signs of dementia had been common among those with severe CTE. Each year of play increased the odds of a CTE diagnosis by 15%. Although the sample was potentially biased because families of players with symptoms were more likely to participate in the program, the results strongly link CTE to football head trauma. In a Harvard study of 1,980 retired football players whose careers spanned from 1960 to 2020, 681 perceived they had CTE and of these, 230 related suicidal thoughts, and 176 had been diagnosed with Alzheimer’s disease or another form of dementia.
To make play safer for players, the NFL changed several rules. Kickoffs were moved forward five yards to reduce the risk of high-speed collisions, a crown-of-the-helmet rule penalizes top-of-the-helmet contact, and an updated concussion protocol mandates the presence of an unaffiliated neurotrauma consultant at all games. Limiting contact during practice sessions might also be helpful. These changes may mitigate, but certainly will not prevent head trauma.
In the United States, 70% of football players are under age 14, and there are preliminary findings that youth tackle football may be a risk factor for CTE. It is estimated that 5 in every 100 young football players have a concussion each year. Also, former NFL players who began playing football before age 12 fared worse on cognitive assessments than those who started later in their teens, even controlling for the number of years played. The study of the brains of deceased football players found a link between early play and CTE. Those who began playing tackle football before age 12 developed cognitive and behavioral symptoms on average 13 years earlier than those who started playing later in their teenage years. Researchers at the Virginia Tech Helmet Lab found that risks start at an early age. Studying players ages 9 to 12, they found that about 8% of head impacts were of high magnitude, disproportionately affecting quarterbacks, running backs and linebackers.
Recognition of the risks associated with playing football is having an impact on youth participation. According to an Aspen Institute State of Play report, participation by 6- to 12-year-olds in tackle football has dropped 29% since 2016, but that drop varies across different racial groups, geographic areas and socio-economic levels. Black and Hispanic students and those from low-income families are more likely to be playing than their white or more affluent counterparts. For minorities, the risk-reward calculus still tilts in favor of playing. An exception is in the South, where Friday-night football reigns supreme in the fall, and white students still play football in substantial numbers.
It’s far too early to predict the demise of tackle football in America, but recent youth participation trends seem to be taking us in that direction. Americans may love football, but they should pay serious mind to the grim statistics around CTE before they decide whether participation in the sport is worth the risk to their health.
Beryl Rosenstein is professor emeritus of pediatrics at Johns Hopkins Medicine.
