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The Study on CTE In Soccer Is Not What You Think It Is

Most studies aren't worth reporting on. This was one of them. Unfortunately, that didn't happen.
TFW you're jumping to irresponsible scientific conclusions. © Kelvin Kuo-USA TODAY Sports

On Tuesday, researchers in the UK published a study they've been working on since 1980. They tracked 14 retired soccer players with dementia, 13 professionals and one "committed amateur." The group averaged 26 years of playing experience. Six of the 14 players had their brains examined after death. Four of those six brains were found to have CTE.

Given all we have learned over the past two decades regarding head trauma in sports, and given who these men were and what they spent their lives doing, this is less than surprising. It is an expected result, and my first reaction was surprise that two of the six brains examined did not have CTE.


Why? Because this study used a sample group about as cherrypicked as one can possibly imagine: a high-risk group (professional soccer players who played mid-century when heavy, leather balls were used) is narrowed down to an even higher risk group (who specialized in heading the ball a lot for two-plus decades) and then to an even higher risk group (who were diagnosed with dementia in their 60s).

This isn't to say the study is useless. It's not useless, but it's useful mostly as part of a broader process. This is just how science works: you first need to establish the presence of a disease in a particular population before launching more rigorous, time-intensive, and resource-consuming controlled studies about its prevalence. Later, you study how to prevent it.

Unfortunately, this was not how the study was reported in the press. Last night and into today, It got picked up by nearly every major paper or site: The Guardian, CNN, The Independent, The Daily Mail, CBS, ESPN, The Telegraph, and so on. Remember, the study was just published yesterday.

The mere fact that a study of marginal scientific importance—it proved nothing new and suggested little we don't already know about CTE, soccer, and head trauma—became instant international news demonstrates that almost nobody reporting on it really understood the topic, the study, or its ramifications.

And that's even before reading the fist sentences. Here was the Telegraph's lede:


"Professional football is as risky as boxing in causing brain damage that can lead to dementia and early death, a major new investigation warns."

I did a literal spit-take when I read this sentence. It's as if a bunch of scientists had created a perfect prototype of Bad Popular Science Reporting in a petri dish. Let's just clarify that: in no, way, shape, or form does the study warn that "professional football is as risky as boxing in causing brain damage." In fact, the only time the study mentions the word "boxing" is when it points out two of the study's participants were amateur boxers (which, by the way, none of the articles felt the need to mention).

The PA Sport lede, as picked up by ESPN, isn't much better:

"Footballers who repeatedly head the ball can end up suffering from dementia, new findings have suggested, prompting calls for more research into a long-suspected issue in the sport."

Again, the study doesn't say this. Firstly, every single participant in this study had dementia, so this was most definitely not a study about whether heading the ball leads players to "end up suffering" dementia. Second, CTE is not dementia. Third, the researchers have no idea what type of head impact resulted in CTE. Heading the ball likely played a part, but so did colliding with other players in the air over the thousands of times they contested headers. This study sheds no light—zero, none, not one photon—on the causes of CTE. And the articles go on like this, completely misrepresenting the study's findings with sensationalist warnings.

Head trauma and soccer absolutely should be studied, particularly its effects on children and young adults playing now or recently under current rules and with similar equipment to that used today. And those studies should be reported on, so that governing bodies, leagues, coaches, players, and parents can make informed decisions about health risks. This particular CTE study checks off none of the above boxes. Unless your job is studying CTE, you should ignore it.