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NFL's Skewed Science

Kavitha A. Davidson is a former Bloomberg View columnist.
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As football's concussion crisis continues to linger, it has also bolstered the growing field of sports medicine, which is addressing the need for more study on brain injuries in sports. It's important to keep a skeptical eye on who's conducting the research and who's funding it.

A paper published last month in the American Journal of Sports Medicine by researchers at the Vanderbilt University School of Medicine reviewed several studies on concussions among NFL players and found them inadequate. The researchers concluded that:

(1) The study of concussions in the NFL has been limited by a lack of recent empirical data, reliance on self-reported concussion history, and ascertainment bias of brains donated for autopsy studies. (2) Further prospective research is especially needed to clarify long-term cognitive, psychiatric, and neuroanatomical effects of concussions, with the importance of complete medical, family, and social history data in mind. (3) Until prospective studies with the methodological improvements outlined above become available, conclusions should be drawn with considerable caution and should be considered tentative at best.

We can all agree that concussions need more research; a definitive link between football-related head injuries and post-retirement depression or suicide has yet to be established, despite several reports from former players, including Terry Bradshaw, Tony Dorsett and the late Junior Seau. But it seems odd to complain about a "lack of recent empirical data," then call for skepticism of the data we do have. That is, until you read this footnote:

One or more of the authors has declared the following potential conflict of interest or source of funding: G.S.S. has served as the consulting neuropsychologist for the Tennessee Titans since 1999, and either he or his employer has received consulting fees for clinical services rendered.

According to Vanderbilt's website, co-author and neuropsychologist Gary S. Solomon -- "G.S.S."-- has been the Titans' team neuropsychologist for 16 years. He's published several papers on brain issues in sports dating back to at least 2007. 

The conclusions of some of Solomon's studies often seem to lean in the NFL's favor: One study from April 2014 concluded that concussion history didn't affect performance on the Wonderlic test, suggesting that "a history of concussion may not have adverse effects on neurocognitive functioning." But the validity of the Wonderlic test has long been in doubt, especially with regard to head injuries. Another 2014 study concluded that chronic traumatic encephalopathy, or CTE, in professional athletes "may not be related solely to concussion and/or sub-concussive injury." And in 2012, he told the Tennessean that new guidelines and penalties were making a positive impact on player safety, casting doubt on the role degenerative brain disease plays in suicide among former players. 

It's a softer approach than that taken by neurologist Ira Casson, former co-chair of the NFL's Mild Traumatic Brain Injury Committee, who adamantly denied the link between concussions in football and long-term neurological damage. Casson was forced to resign in 2009 after many of his views were dismissed as biased and medically unsound. Despite his repeated insistence that he's "a man of science" and not a de facto league spokesman, Casson repeatedly said concussions don't lead to Alzheimer's or other diseases, telling Congress in 2010 that "there is not enough valid, reliable, or objective scientific evidence at present to determine whether or not repeat head impacts in professional football result in long-term brain damage." An independent doctor said "no sports medicine physician I know would agree with him."

Casson hasn't gone away quietly: Just last year, he co-authored a study that concluded that "the majority of retired NFL players had no clinical signs of chronic brain damage." Additionally, the report includes an odd field called "Clinical Relevance," not found in the majority of other abstracts, which reads as little more than editorializing: "These results need to be reconciled with the prevailing view that a career in football frequently results in chronic brain damage." And, unlike in Solomon's study, the footnotes state that "the authors reported no potential conflicts of interest in the development and publication of this manuscript."

It's right out of the NFL's playbook of whitewashing years of scientific research detailing the sport's neurological impact on players. In their book "League of Denial," reporters Mark Fainaru-Wada and Steve Fainaru described the league's attempts to quell the cries from independent researchers -- attempts that included commissioning its own research. As ESPN's Don Van Natta noted in 2013, among that research's dubious conclusions was that "multiple concussions did not increase the risk of further injury."

The strategy -- which seems to have shifted from flat-out denials that football-related head injuries don't cause long-term damage to league-affiliated researchers simply casting doubt on others' scientific conclusions -- is codified at the highest levels of power in the NFL. In his own testimony before Congress, Commissioner Roger Goodell repeatedly evaded direct questions about the link between concussions and long-term brain damage, deferring to the medical community "to continue that debate."

The NFL commissioning its own research in order to manufacture doubt is right out of the playbook of another evil empire: Big Tobacco. A study by researchers at the University of California at Davis and UC San Francisco revealed that the tobacco industry "funded and used scientific studies to undermine evidence linking secondhand smoke to cardiovascular disease." Rather than come out and conclude that secondhand smoke was unequivocally not harmful, many of these studies "were used to call into question other evidence" pointing to its dangers.

Doubt has proven to be these industries' most powerful tool in using junk science to their advantage and discrediting legitimate research. But what we should really doubt is a concussion study leaning in the NFL's favor conducted by anyone receiving a paycheck from a team's front office.

This column does not necessarily reflect the opinion of Bloomberg View's editorial board or Bloomberg LP, its owners and investors.

To contact the author on this story:
Kavitha A. Davidson at kdavidson19@bloomberg.net

To contact the editor on this story:
Brooke Sample at bsample1@bloomberg.net