Any way you slice it, American football is simply not healthy for players in the long term. Recent high-profile cases, like Aaron Hernandez’s untimely suicide, have highlighted the connection between traumatic brain injury — the repeated impacts that players sustain throughout a career — and chronic traumatic encephalopathy, a neurodegenerative disease whose symptoms include dementia, depression, and aggression.

In 2017, scientists found molecular evidence connecting repeated TBI with CTE, which supported the idea that the danger exists in NFL players. But this study failed to show which players have higher rates of CTE and other health issues than the general population. The problem was that there was no control group: comparing the health of NFL players to regular people is hardly a fair basis for comparison.

Fortunately, researchers behind a Journal of the American Medical Association paper published Thursday thought to take advantage of a three-game, league-wide NFL player strike in 1987 in their new study, which provided them with the opportunity to compare the health of short-term replacement players with that of career NFL players.

brain CTE football NFL
Researchers examine a brain donated by ex-players for signs of CTE.

The team, led by Atheendar Venkataramani, M.D., Ph.D., an assistant professor of medical ethics and health policy at the University of Pennsylvania’s Perelman School of Medicine, compared the long-term health outcomes of 879 replacement players that played in 1987 to those of 2,933 “career” NFL players who debuted between 1982 and 1992.

The analysis didn’t turn up a significant difference in all-cause mortality — that’s death for any reason in a certain time period — between the two groups, which seems to run counter to the idea that football is bad for long-term health. But in the paper, the study authors point out several limitations of this research: “Given the small number of events, analysis of longer periods of follow-up may be informative,” they write.

While using the replacement players as a control group certainly boosted the experiment’s design, they’re still not a perfect basis for comparison, and this should be taken into account when assessing the results. Replacement players played an average of only three games; in contrast, the average NFL career, across all positions, is 2.66 years, according to a 2016 Wall Street Journal analysis (in this study, career players played a median number of five seasons).

Additionally, the study period only included a small number of deaths. At the time the data collection ended, in December 2016, 144 of the career players had died (4.9 percent), and 37 of the replacement players had died (4.2 percent). These are relatively small numbers, which mean that any results drawn from them may not be statistically significant.

By looking to the replacement players for comparison, this study improves upon previous studies on the health of NFL players but still highlights the difficulties researchers will face as they continue to try and figure out just how at-risk professional footballers are. The data are simply not available — at least not yet; for better or worse, there will be more information on the long-term health issues of NFL players as the league continues to operate with the same old safety policies. At the very least, it seems the league is no longer calling the science into question and has since begun funding research into the long-term risks of the sport.

Abstract:

IMPORTANCE Studies of the longevity of professional American football players have demonstrated lower mortality relative to the general population but they may have been susceptible to selection bias.

CONCLUSIONS AND RELEVANCE Among NFL football players who began their careers between 1982 and 1992, career participation in the NFL, compared with limited NFL exposure obtained primarily as an NFL replacement player during a league-wide strike, was not associated with a statistically significant difference in long-term all-cause mortality. Given the small number of events, analysis of longer periods of follow-up may be informative.