The following is a guest blog post from one of our regular contributors and reviewers, Susan Molchan, MD, a psychiatrist in the Washington, DC, area.
Over the past several years many stories in the media, as well as last winter’s movie, Concussion, have reported on the increased incidence of Alzheimer’s disease, amyotrophic lateral sclerosis (ALS or Lou Gehrig’s disease) and chronic traumatic encephalopathy (CTE) in former professional football players. The National Football League (NFL), which has financial, legal, and public relations stakes in the matter, has downplayed data on risks, as detailed in this timeline from Lauren Ezell in Frontline, and in an article in The New York Times last month by Alan Schwarz, Walt Bogdanich, and Jacqueline Williams. The latter reported that research overseen by the NFL likely underestimated concussion rates, as many concussions were not included in the data. Several teams reported no concussions in players for years, contradicting injury reports and even reports in the media.
With this context in mind, would you be surprised if an expert from a rather football-focused university — who also happens to serve on the NFL’s advisory committee regarding head injuries — said the risks of concussions in football have been overstated? Me neither. And I’d certainly want whatever media source carried the claim to disclose the expert’s association with the NFL.
NFL affiliation never addressed in PR release
But that’s not what happened with a news release from the medical center at Penn State University headlined “True Dangers of Concussion and CTE Often Misunderstood.” The release quotes Dr. Robert Harbaugh, neurosurgeon and director of the Penn State Institute of Neurosciences, who says the problem of CTE related to contact sports “has been overstated and it has scared a lot of parents out of letting their children participate in these sports.”
But the release failed to disclose Dr. Harbaugh’s role as the leader of an NFL subcommittee studying the long-term effects of concussions. Dr. Harbaugh’s link to the NFL was pointed out by Chris Nowinski, the founding executive director of the Concussion Legacy Foundation and co-founder of Boston University’s Chronic Traumatic Encephalopathy (CTE) Center. Mr. Nowinski also said the release contained errors and felt it diminished the risks of CTE.
— Chris Nowinski (@ChrisNowinski1) March 17, 2016
While I didn’t see anything grossly inaccurate, most of the key information we look for in health care-related news releases was noticeably absent. For example, almost no data (or links to data) were provided. The only quantification in the release was this: “…the largest study of NFL players shows that more than 90 percent don’t develop these problems.” But how does that “more than 90 percent” compare to the general population?
The lack of transparency was also problematic. In an email, Dr. Harbaugh confirmed he receives no compensation for his work with the NFL committee and his opinions are his own, and not influenced by his role on the committee. Still, it’s vitally important for readers to know that this information is coming from someone with close ties to the league.
Does anyone really know the “true dangers” of concussions?
I also found the headline for the news release to be misleading. We’ll never know the “true” dangers of concussion for any individual or even group, and certainly don’t know them now. As we learn more we’ll likely get a better fix on the risks. But the release oversteps by suggesting that it contains hidden nuggets of wisdom on this issue.
A more accurate headline might have said something along the lines of, “Dangers of concussion and CTE are not understood.”
I was pleased to see that the release does include the perspective of a second physician source who does not serve on an NFL committee.
As far as accuracy, Mr. Nowinski took issue with the statement, “ . . . it is impossible to tell if [CTE] is the result of head trauma alone or other factors, including genetic predisposition . . . “. In an email, he made the point that the pattern of CTE pathology has been found only in the brains of people with a history of brain trauma.
This is a subtle point and the key word is “alone.” Many if not most diseases are the result of a variety of factors, not all of which we understand. We still have much to learn about what predisposes to CTE. Not all professional players or people with repeated head trauma develop CTE, so as Dr. Harbaugh said in an email, “trauma may be a necessary but not sufficient cause.”
The same could be said for lung cancer, which does not develop in all people who smoke, or liver cirrhosis, which does not occur in all heavy drinkers. Besides genetics in pro football players, other factors that may contribute to CTE could include use of steroids, and drugs to medicate the arthritis and chronic pain many deal with in retirement.
In medical studies, hindsight is not 20/20
Studies documenting the risks of head injury are retrospective, and such backward-looking data are particularly susceptible to confounding factors. For example, compared with the brains of players in better overall health, the brains of football players with serious problems are more likely to land on the table of a pathologist for examination. In addition, the involvement of famous players and extreme behavior such as suicide may have served to amplify our perception of the problem. Scientists are calling for prospective studies to help clarify the risks, so they have a better idea of individuals’ health and risk factors both before they enter the studies and while they are taking part in them.
As Dr. Harbaugh acknowledged in the news release, the rate of degenerative brain diseases seems higher in professional football players than in the general population. For example, a study of death certificates of retired NFL players found they died of neurodegenerative disease, particularly Alzheimer’s disease and ALS, three times as often as the general population (although their risk of death overall was significantly lower). The study authors noted that interpretation of the results is limited by the small number of cases recorded (7 each of Alzheimer’s and ALS). Here’s another concern: the median age of the 3,439 players studies was only 57 years — and most degenerative brain disease happens much later in life. As the years pass, I suspect that those who’ve been subjected to head trauma will experience even more of a disease burden.
Risks from football and risks from doing nothing
As some of the most elite athletes in U.S. society, professional football players fly close to the sun. Many will come away with damaged bodies. They know the risks and have decided the tradeoff is worth it. It’s different for children, and as the news release notes, no evidence indicates any increased risk of brain disease in people who played football in high school. This lack of evidence doesn’t preclude increased risk, however, as studies are necessarily retrospective and may miss some data. But it’s reassuring as far as it goes.
From a broader standpoint, as Dr. Harbaugh notes in the news release, childhood obesity is out of control. I’d add that obesity and its attendant affliction diabetes are also risk factors for dementia and of course many other diseases. In the long-term scheme of things, sitting in front of a computer screen for hours may prove to be a greater risk for the average young Joe than getting outside to play, whatever the sport.