The 2015-16 football season is underway, and to many, this means touchdowns, TV, and triumphant storylines. However, to Dr. Ann McKee, chief of neuropathology at the New England Veterans administration center, it means something a little darker.
Researchers at the Department of Veterans Affairs and Boston University have found that 87 of 91 deceased National Football League (NFL) players had chronic traumatic encephalopathy (CTE). The figure is startling. It indicates a clear correlation between playing football and CTE, a progressive neurodegenerative disease.
Currently, CTE can only be diagnosed post mortem. Due to this restraint, researchers have relied on former players to donate their brains to science in order to study its degree of incidence. McKee’s team analyzed the brains of 165 individuals who played high school, college, or professional football. The overall incidence of CTE was 79 percent, or 131 out of 165. This data suggests that NFL players have a more extensive history of brain trauma in comparison to their college and high school counterparts.
Some believe that the data is sensationalized to try to present a problem that does not exist. They cite that players who donated their brains were more likely to suspect cognitive issues during their life. This selection bias is a valid concern. McKee’s team cannot establish external validity for their study until they can find a sample that is representative of the larger population of players. Even with this limitation, McKee claims that their research is consistent with previous findings. She told PBS, “People think that we’re blowing this out of proportion, that this is a very rare disease…My response is that, where I sit, this is a very real disease. People want to make this just Alzheimer’s disease or aging and not really a disease. I think there are fewer of those people [now], but that’s still one of our major hurdles.”
McKee is not alone in making this statement. A study conducted earlier this year by Dr. Munro Cullum, a neuropsychologist at the University of Texas Southwestern Medical Center, and his team found that NFL players who experienced a Grade Three concussion (loss of consciousness) at some point in their careers had a smaller hippocampal volume than those who had not. These same players also performed poorly on verbal memory tests, which was reflective of the shrinkage in hippocampal volume. A high incidence of memory impairment among NFL players who have experienced sustained brain trauma is consistent with the findings of McKee’s study because they are indicative of a post mortem diagnosis of CTE. Although McKee’s sample is not perfectly representative of the full population of NFL players, it is likely that many NFL players will exhibit some of the clinical symptoms of CTE (including depression, dementia, anxiety, and aggression) later in life.
It would be a misconception to think that CTE is only the result of one violent collision. The disease can be, and most often is, a result of repetitive hits to the head that may not necessarily have to be symptomatic. For example, 40 percent of the players who had CTE in McKee’s study were either offensive or defensive linemen. Linemen experience physical contact on every play. Although they may not even experience a concussion from a violent hit in their careers, they are more susceptible to CTE due to continuous sub-concussive hits to the head. It is worrisome that athletes may be increasing their risk for CTE without knowledge.
With the risk of CTE high among football players, is it plausible to allow our children to play high contact sports? The answer is both yes and no. Many high contact sports, including football, hockey, and lacrosse are great opportunities for children to get physical activity and acquire team-building skills. With an increasing problem of obesity in the United States, it seems illogical to dissuade parents from letting their children get their much-needed exercise. However, it has been found that the younger brain is more vulnerable to injury than the older brain. A study by Dr. Robert Stern, a professor of neurobiology at Boston University, found that NFL players who started playing tackle football before the age of 12 performed considerably worse on memory tests in comparison to those who started playing tackle football after the age of 12. Stern told HealthDay, “Participation in youth sports is tremendously beneficial. But parents should be aware of this. And if there is an option to play, say, flag football at that age — where one can learn all of the important social skills of team participation and have as much fun, but take the brain out of it — then I say we should do that.”
The issue is one current and future parents will have to contemplate. As more and more data comes in, the harsh reality is that there is a strong link between neurodegenerative disease and high contact sports. This does not mean that we must cease to participate in these sports, but rather, that a solution needs to be developed, and fast.