Summary: Researchers have found a possible association between playing organized tackle football and a higher likelihood of being diagnosed with Parkinson’s disease (PD) or parkinsonism. Analysis of a large online dataset indicated that men who reported playing tackle football had substantially greater odds of reporting a PD diagnosis than men who played other sports, with the highest competitive levels showing the strongest associations.
Using data from an online longitudinal study, investigators observed that participants with a history of organized tackle football had 61% higher odds of reporting parkinsonism or a PD diagnosis. Men who played at the college or professional level had even greater odds of a reported diagnosis compared with those who only played at youth or high school levels. The authors emphasize that this relationship does not mean every football player will develop PD, as many genetic and environmental risk factors contribute to the disease.
Key Facts:
- Men who reported playing organized tackle football had 61% increased odds of a self-reported diagnosis of parkinsonism or Parkinson’s disease.
- Football players who competed at college or professional levels had nearly three times the odds of reporting a PD diagnosis compared with players who only participated at youth or high school levels.
- The study contrasted football players with athletes from other sports, strengthening the comparison and reducing some alternative explanations.
Source: Boston University
Background: Identifying risk factors for Parkinson’s disease is important for earlier recognition and potential prevention strategies. Historical accounts dating back to the 1920s have linked repetitive head trauma in boxing with parkinsonism. Repetitive head impacts from American tackle football are also known to be associated with long-term neurological outcomes such as chronic traumatic encephalopathy (CTE), but research directly testing the relationship between football participation and PD has been limited.
In the largest study to date examining this association, researchers at the Boston University CTE Center analyzed data from Fox Insight, a large online cohort that enrolls people with and without Parkinson’s. The analysis included 1,875 men who reported participating in organized sports: 729 men who had played football (mostly at amateur levels) and 1,146 men who had played other sports and served as a comparison group.
Participants in Fox Insight completed online questionnaires and self-reported whether a physician or other health professional had ever diagnosed them with Parkinson’s disease or parkinsonism. The Boston University Head Impact Exposure Assessment module was launched in November 2020 to collect more detailed information about repetitive head impacts; the data used for this study were extracted on June 9, 2022.
After adjusting for age, education, body mass index, history of diabetes or heart disease, history of traumatic brain injury with loss of consciousness, and family history of PD, the researchers found that a history of playing football was associated with higher odds of reporting parkinsonism or PD (odds ratio [OR], 1.61; 95% CI, 1.19–2.17). Longer duration of football play was linked to greater odds overall (OR, 1.12 per year of play; 95% CI, 1.06–1.19) and among football players specifically (OR, 1.12; 95% CI, 1.02–1.23). Higher competitive level—college or professional play—was associated with markedly higher odds of a reported diagnosis (OR, 2.93; 95% CI, 1.28–6.73) compared with youth or high school play. Age at first exposure to football was not associated with increased odds in this sample.
“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),” said Michael L. Alosco, PhD, associate professor of neurology at Boston University Chobanian & Avedisian School of Medicine and corresponding author. He cautioned that the mechanisms underlying the relationship remain unclear and that many who play tackle football will not develop later-life neurological conditions.
The study’s comparison of football players with athletes from other sports is a notable strength, and most participants had only played tackle football at amateur levels—addressing a gap in prior research that often 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 observed in boxers, American football might also affect risk for other neurodegenerative conditions such as PD,” said Hannah Bruce, MSc, first author and research specialist at Boston University Chobanian & Avedisian School of Medicine.
Limitations: The authors note several important caveats. The sample was a convenience cohort enriched for people with PD and was predominantly White, which limits generalizability. PD and parkinsonism diagnoses were self-reported online rather than confirmed via standardized in-person clinical assessments. These preliminary findings call for additional studies using objective diagnostic methods, more diverse populations, and prospective designs to better define any causal relationship.
Funding: This research was supported in collaboration with The Michael J. Fox Foundation for Parkinson’s Research, which sponsors the Fox Insight study. Additional grant funding came from the National Institute of Neurological Disorders and Stroke (NINDS) under awards U54NS115266 and K23NS102399.
Conflicts of Interest: Several authors are staff members of The Michael J. Fox Foundation. Additional disclosures include consulting relationships and advisory roles for various companies by specific authors. One author has received honoraria and royalties unrelated to this study. Remaining authors reported no conflicts.
About this Parkinson’s disease research news
Author: Gina DiGravio
Source: Boston University
Contact: Gina DiGravio – Boston University
Image: The image is credited to Neuroscience News
Original Research: Open access. “Association Between American Football Play and Parkinson’s Disease” by Michael L. Alosco et al., published in JAMA Network Open.
Abstract
Association Between American Football Play and Parkinson’s Disease
Importance: Parkinsonism and Parkinson’s disease have long been linked to repetitive head impacts in boxing. Similar repetitive head impacts in American football may also be associated with increased risk of neurodegenerative pathologies that cause parkinsonism, but in vivo research on the association between football play and PD has been limited by small samples and inconsistent results.
Objective: To evaluate whether participation in organized American football is associated with self-reported parkinsonism or PD diagnosis.
Design, Setting, and Participants: This cross-sectional analysis used data from the online Fox Insight study. Participants completed online questionnaires and reported whether a clinician had diagnosed them with Parkinson’s disease or parkinsonism. Data for the Head Impact Exposure Assessment were collected beginning in November 2020; the dataset used in this analysis was retrieved on June 9, 2022. The analytic sample included 1,875 men who reported playing organized sports, of whom 729 (38.9%) reported football play.
Exposures: Self-reported history of football participation, duration and highest level of play, and age at first exposure.
Main Outcomes and Measures: Logistic regression assessed associations between PD status and history of football play, duration of play, highest level reached, and age at first exposure. Models adjusted for age, education, diabetes or heart disease history, body mass index, history of traumatic brain injury with loss of consciousness, and family history of PD.
Results: The sample included 1,875 men (mean age 67.7 years) enriched for parkinsonism or PD (n = 1,602, 85.4%). Football history was associated with higher odds of a reported parkinsonism or PD diagnosis (OR, 1.61; 95% CI, 1.19–2.17). Longer overall duration of play and, among football players, longer duration of football play and higher level of competition were each associated with increased odds of a reported diagnosis.
Conclusions and Relevance: In this cross-sectional sample enriched for PD, participation in football was associated with higher odds of reporting parkinsonism or Parkinson’s disease. Further research is needed to confirm these findings, clarify underlying mechanisms, and determine clinical implications.