Recent research indicates heightened risks with extended duration of play, including among high school and college athletes.
Recognizing risk factors for Parkinson’s disease (PD) is crucial for early detection. Since the 1920s, both Parkinson’s disease and parkinsonism—a broader term that encompasses motor symptoms seen in PD and other disorders—have been observed in boxers.
Repeated head traumas from tackle football can lead to serious neurological conditions such as chronic traumatic encephalopathy (CTE). Nonetheless, there is limited research on the link between playing tackle football and the onset of PD.
In the largest study to describe the association between participation in football and the odds of having a reported diagnosis of PD, researchers from the BU CTE Center used a large online data set of people concerned about having PD and found participants with a history of playing organized tackle football had a 61% increased odds of having a reported parkinsonism or PD diagnosis.
In this study, the researchers evaluated 1,875 sports participants — 729 men who played football, predominantly at the amateur level, and 1,146 men who played non-football sports who served as the control group. Participants were enrolled in Fox Insight, a longitudinal online study of people with and without PD sponsored by The Michael J. Fox Foundation for Parkinson’s Research.
Notably, researchers found a link between playing football and increased odds of having a parkinsonism or PD diagnosis even after accounting for known risk factors for PD. Additionally, the data revealed that players who had longer careers and played at higher levels of competition experienced increased odds of having a reported diagnosis of parkinsonism or PD.
Football players who played at the college or professional level were at 2.93 increased odds of having a PD diagnosis compared with those who just played at the youth or high school level. The age of first exposure to football was not associated with the odds of having a reported parkinsonism or PD diagnosis.
“Playing tackle football could be a contributing risk factor to PD, particularly among people already at risk due to other factors (e.g., family history). However, the reasons for this relationship are not clear and we also know that not everyone who plays tackle football will develop later-life neurological conditions, meaning many other risk factors are at play,” says corresponding author Michael L. Alosco, PhD, associate professor of neurology at Boston University Chobanian & Avedisian School of Medicine.
The researchers also emphasized that they compared the football players to another group of athletes, a noteworthy strength of the study. Furthermore, most of the participants played tackle football only at the amateur level, which is in contrast to most of the research to date that has focused on professional athletes.
“Previous research has focused on the association between American football and risk for CTE. However, similar to what has historically been seen in boxers, American football might also affect risk for other neurodegenerative conditions such as PD,” says Hannah Bruce, MSc, first author and research specialist at Boston University Chobanian & Avedisian School of Medicine.
The researchers acknowledge several limitations to their findings and caution that the work is still preliminary. It was a convenience sample of people enriched for having PD who were mostly white, thereby limiting the generalizability of the findings. Diagnosis of PD was also self-reported by participants through online assessments and objective in-person evaluations were not conducted.
Reference: “American Football Play and Parkinson Disease Among Men” 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 and Michael L. Alosco, 11 August 2023, JAMA Network Open.
This work was in collaboration with The Michael J. Fox Foundation for Parkinson’s Research, the sponsor of Fox Insight. The Fox Insight study was used to collect and aggregate data used in this manuscript. Grant funding was also from NINDS (U54NS115266; K23NS102399).
Several authors are staff members at The Michael J. Fox Foundation for Parkinson’s Research, the sponsor of Fox Insight. CHA consulted for Avion, CND Life Sciences, Jazz, and Precon Health. RAS is a paid consultant to Biogen (Cambridge, MA, USA). He is a member of the Board of Directors of King-Devick Technologies, Inc. (Chicago, IL, USA), and he receives royalties for published neuropsychological tests from Psychological Assessment Resources, Inc. (Lutz, FL, USA). He is a member of the Medical Science Committee for the National Collegiate Athletic Association Student-Athlete Concussion Injury Litigation. Chris Nowinski is a volunteer member of the Mackey-White Committee of the NFL Players Association and compensated advisor to Oxeia Biopharmaceuticals. Ann C. McKee is a member of the Mackey-White Committee of the NFL Players Association. MLA has received honorarium from The Michael J Fox Foundation for services unrelated to this study. He also receives royalties from Oxford University Press. The remaining authors have no conflicts of interest to disclose.