A survey of former male athletes showed that those who reported playing American football had around 60% higher odds of having Parkinson’s disease compared to men who reported playing other sports. Participants who played football longer were even more likely to have Parkinson’s disease. The study was published in JAMA Network Open.
Parkinson’s disease is a neurodegenerative disorder primarily affecting movement control. It is characterized by the gradual loss of dopamine-producing neurons in the brain, resulting in symptoms such as tremors, rigidity, slowness of movement, and postural instability. While there is no cure for Parkinson’s disease, various treatments, including medication, physical therapy, and sometimes surgery, can help manage its symptoms and enhance the quality of life for individuals living with the condition.
Apart from Parkinson’s disease, several other neurological disorders exhibit some of the same characteristic symptoms, collectively referred to as parkinsonism. Although the exact causes of parkinsonism and Parkinson’s disease remain incompletely understood, it is known that both can be attributed to repetitive head impacts, which are often sustained in activities like boxing, including repeated hits, blows, and head impacts during boxing matches.
Players of American football also endure similar head impacts during the course of a game. Consequently, it is plausible that playing football may be associated with an increased risk of Parkinson’s disease or parkinsonism.
Study author Hannah J. Bruce and her colleagues wanted to evaluate the association between playing American football and self-reported diagnosis of parkinsonism or Parkinson’s disease. They analyzed data from the Fox Insight study, a longitudinal online study encompassing people with and without Parkinson’s disease, operated by the Michael J. Fox Foundation to explore the experiences of individuals with Parkinson’s disease. The study enrolled over 50,000 adult participants.
For this analysis, the study authors utilized data from the 2020 Boston University Repetitive Head Impact Exposure assessment conducted within the Fox Insight study. This assessment focused on exposure to repetitive head impacts from contact sports and compared these participants to athletes engaged in noncontact sports.
The data encompassed 1,875 former athletes, all of whom had played some form of organized sport. These individuals were categorized into those who had participated in American football (constituting 39% of the group) and those who had engaged in other sports. The average age of the participants was 68 years, with those who played American football, on average, reporting over 4 years of play.
Participants reported their Parkinson’s disease or parkinsonism status, their history of participating in organized American tackle football, the age at which they began playing, the highest level at which they played (youth, high school, college, or professional), and the number of seasons they played at each level. The study authors tabulated the years of professional play and fall seasons played at a non-professional level, with the fall season being significant because it corresponds to the primary season for American football.
The results indicated that, aside from American football, other common contact sports included soccer (23.7% of participants), ice hockey (9.2%), amateur wrestling (6.1%), and boxing (4.9%). The most prevalent noncontact sports were baseball (24.1%), basketball (17.8%), and tennis (8.3%).
Notably, 82.4% of participants who reported playing American football had done so at the youth or high school level, and 85.4% of participants reported having either parkinsonism or a Parkinson’s disease diagnosis. This percentage was even higher, at 88.9%, among football players.
(It is important to note here that study participants were selected for a study on Parkinson’s disease. These rates are far higher than the rates of Parkinson’s disease and parkinsonism observed in the general population. Estimates suggest that only approximately 1% of people between the ages of 65 and 75 suffer from Parkinson’s disease.)
American football players had slightly over a 60% higher likelihood of developing parkinsonism or Parkinson’s disease compared to athletes who participated in other sports. Furthermore, participants who played American football for more seasons and at higher levels had progressively higher odds of developing parkinsonism or Parkinson’s disease.
However, the age at which participants began playing American football did not influence the likelihood of developing parkinsonism. The odds of developing parkinsonism or Parkinson’s disease increased even further when participants from sports that also often involve head impacts, such as boxing, were excluded from the group of participants not playing American football. In other words, the comparison was made exclusively between former American football players and participants in noncontact sports.
“In this cross-sectional study, there was an association between participation in American football and higher odds of self-reported parkinsonism or Parkinson’s disease. Among football players, odds of having a parkinsonism or Parkinson’s disease diagnosis were greater with more seasons and higher level of football play. The findings suggest that American football participation might be a risk factor for developing parkinsonism or Parkinson’s disease, the study authors concluded.
The study sheds light on the links between playing American football and developing parkinsonism later in life. However, it also has limitations that need to be taken into account. Notably, the study used a very selected group of people, many of which were included in the study particularly because they had parkinsonism. The share of individuals with parkinsonism in the general population is many times lower. Additionally, the study design does not allow any cause-and-effect conclusions to be derived from the data.
The study, “American Football Play and Parkinson Disease Among Men”, was authored by Hannah J. Bruce, Yorghos Tripodis, Michael McClean, Monica Korell, Caroline M. Tanner, Brittany Contreras, Joshua Gottesman, Leslie Kirsch, Yasir Karim, Brett Martin, Joseph Palmisano, Bobak Abdolmohammadi, Ludy C. Shih, Thor D. Stein, Robert A. Stern, Charles H. Adler, Jesse Mez, Chris Nowinski, Ann C. McKee, Michael L. Alosco.
