Is American football associated to higher Parkinson's disease risks?

Repeated head trauma in boxing, increases the risk of neurodegenerative disorders and Parkinson's. What about the USA's most popular sport?

Possible causes of Parkinson's disease

Neurological diseases are now the leading cause of disability worldwide, while the fastest growing neurological disease is Parkinson's.1 As there is currently no curative treatment available, research into avoidable causes of the sharp rise in new cases is playing a key role. In addition to genetic factors, environmental risk factors are increasingly being recognised, such as exposure to toxins and pesticides. Furthermore, cerebrovascular diseases in combination with risk factors such as diabetes and hypertension can cause vascular parkinsonism. Traumatic brain injury is another recognised aetiology.

Parkinson's in American football players: how high is the risk?

In 2020, the Boston University Head Impact Exposure Assessment was created to collect data on repeated head impacts. For the current analysis, a subpopulation with a particularly high number of Parkinson's cases (85%) was selected. The study included 1,875 formerly athletically active men with an average age of 68 years who self-reported their diagnoses via online questionnaires. Former athletes were divided into those who had played American football (n = 729 or 39%) and those who played other sports (reference group).

Former participation in American football was associated with a 61% higher probability of a later Parkinson's diagnosis, according to the cross-sectional data. A longer athletic career and a higher level at which players were active were associated with almost three times the odds of Parkinson's (compared to men who had only played in youth leagues or high school).2

The association persisted after accounting for several other factors, including age, education, pre-existing medical conditions (such as diabetes or heart disease), body mass index, history of head trauma with loss of consciousness and positive family history for Parkinson's. "We all realise that the numerous blows over the years have caused serious head trauma." If the study were conducted with today's players, the results would probably be different because the game and training have changed dramatically in the last five to eight years, various coaches are certain.3

John Jacob, head coach of one team and commissioner of the New Jersey Football Coaches Association, says, "My first reaction is that this study is based on a sample of participants who are nearly 70 years old. While the results are certainly significant, we have to remember that the game was played very differently at that time."3

Governing bodies have taken various measures in recent years to make the sport safer, such as contact restrictions in training, fouls for tackling defenceless players and a ban on initiating helmet-to-helmet contact. Also, protective equipment was not nearly as effective back then as it is today3

American football is currently America's most popular sport. The big NFL final, the Superbowl, is the biggest single sporting event in the world with potentially over a billion viewers. Advertising space is therefore so fiercely contested that a 30-second TV advert during prime time now costs up to USD 5 million. For food delivery services, Superbowl Sunday brings in a third of their total annual turnover. And when TV viewers go to the toilet at the same time during the breaks, the waterworks experience bottlenecks.4

  1. Dorsey, E. R. et al. Global, regional, and national burden of Parkinson’s disease, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016. The Lancet Neurology 17, 939–953 (2018).
  2. Bruce, H. J. et al. American Football Play and Parkinson Disease Among Men. JAMA Network Open 6, e2328644 (2023).
  3., K. S. | N. A. M. for. Football might raise risk of Parkinson’s, study finds. But N.J. coaches say it’s safer than ever (2023).
  4. University of Arizona News. "Super Bowl's Super Flush: Just a Super Myth?". 6 February, 2017.