There’s more evidence that playing football can lead to permanent brain damage. But the problem likely isn’t as prevalent as many media accounts have suggested.
Chronic traumatic encephalopathy (CTE) is a progressive neurodegenerative disease associated with repeated head trauma. Symptoms include dementia and mood or behavioral disorders. It was first described in boxers several decades ago, but has been found in NFL players in the past five years.
Last week, researchers at Boston University published a study – the largest to date - looking at the brains of more than 200 deceased football players. 111 of those brains belonged to former NFL players and, of those, 110 had CTE pathology, prompting many news outlets to trumpet the news that researchers had found CTE in 99 percent of the NFL players’ brains they had examined.
Technically, that’s exactly what happened. Still, harping on the 99 percent figure could be misleading. The key is in which brains were part of the study.
This research was based on one brain bank, which is a collection of brains donated by the family members of deceased former football players who exhibited signs of CTE prior to death. In other words, what this study largely did was confirm the CTE diagnosis for football players suspected of suffering from the disease.
“The study was not designed to be a look at the prevalence of CTE in football players,” explained Jesse Mez, assistant professor of neurology at Boston University and the lead author of the new study.
While this study can’t be used to pin down the likelihood of a football player developing CTE, Mez says they have concluded that football poses an increased risk of CTE.
“There seems to be this strong association,” said Mez. “Other brain banks have looked for CTE and haven’t found it, yet in our brain bank, we see it commonly.”
And, since they found mild CTE pathology in the brains of some who didn’t play football beyond high school, Mez says there’s likely no completely safe level of play.
But that doesn’t mean every football player will develop CTE. There are at least 1500 players in the NFL, in any given year. The 110 confirmed cases of CTE in this study represent less than ten percent of that number – not ninety nine percent, as some headlines would have had readers believe.
Still, this study and the growing recognition of the risk of brain damage from repeated head trauma has prompted some high profile retirements. Baltimore Ravens’ offensive lineman (and MIT mathematics graduate student) John Urschel and Patriots’ wide receiver Andrew Hawkins both announced their retirements last week. Hawkins has pledged his brain to research.
Are you a football player, or the parent of one? How does this research affect your plans?