NFL players who reported experiencing symptoms of concussion during their careers showed problems with memory and cognition decades after retirement, according to a study published Thursday in the Archives of Clinical Neuropsychology, bolstering troubling research as concerns grow over the toll paid by athletes competing in America’s most popular sport.
Former National Football League players who recalled having symptoms of concussion—which includes headaches, nausea, dizziness, losing consciousness, disorientation, confusion and seizures—during play or practice performed worse on a series of cognitive tests than their counterparts who did not recall such symptoms, researchers found.
The researchers, who studied 353 retired players an average of 29 years after their careers ended, noted poor cognitive performance was tied to the recollection of concussion symptoms, which is not a formal diagnosis of concussion, but potentially indicates numerous head injuries were not recognized or reported at the time.
The cognitive disparity between players with the highest and lowest reported concussion symptoms were so great they equalled cognitive declines usually observed between people decades apart, the researchers found, with differences in visual memory scores roughly the same as the differences between a typical 35-year-old and 60-year-old.
In a follow-up study comparing the retired players to a group of 5,086 men who did not play football, the researchers found that former players generally performed worse on cognitive tests, and older players performed even worse.
The findings suggest professional football could be accelerating typical age-related cognitive decline and leading to greater disadvantages for retired players as they grow older.
It’s possible younger players have benefited from more awareness, treatment and understanding of head injuries in the sport, and researchers said more work is needed to track former players over time.
It is well-known that cognition can be impaired in the hours and days following concussion, but data on the long-term impact has been mixed, said Laura Germine, senior author of the study. Germine, a professor of psychiatry at Harvard Medical School and director of the Laboratory for Brain and Cognitive Health Technology at McLean Hospital, said these findings show former players “can still experience cognitive difficulties associated with head injuries decades after they have retired from the sport.”
A concussion is a type of traumatic brain injury that affects how the brain functions. Clinicians consider concussion a serious, though usually not life-threatening, problem but they are commonly undiagnosed or unreported. Typically, a concussion is caused by bumps, blows or jolts to the head or body that cause the brain to move around in the skull. Some sports, particularly contact sports like football, naturally carry a risk of injury, including concussion. The issue has become a major flashpoint for the NFL and it has been accused of denying or ignoring decades of science and evidence connecting the sport to long-term brain injury and disability (helmets do very little to address the problem). Chronic traumatic encephalopathy, a type of degenerative brain condition, is common among former players, found in as many as 99%, according to one study. Though the league has made efforts to change its protocols and policies in recent years, many opponents do not believe they are sufficient to mitigate the long-term risks of the sport.
15%. That’s the proportion of U.S. high school students who reported one or more sports or recreation-related concussion within the last 12 months, according to the CDC.