Summary: Researchers identified a potential link between playing tackle football and an increased risk of Parkinson’s disease (PD).
In a study using a large online dataset, participants with a history of playing organized tackle football showed a 61% heightened odds of PD diagnosis. Those who played at higher competitive levels like college or professionally exhibited even greater odds.
Despite the significant findings, the researchers emphasize that not everyone who plays tackle football will develop neurological conditions, as many risk factors are involved.
Participants with a history of playing tackle football had 61% increased odds of a PD diagnosis.
Football players who competed at college or professional levels had nearly triple the odds of a PD diagnosis compared to youth or high school players.
The study notably compared football players with another group of athletes, lending strength to the findings.
Source: Boston University
Identification of risk factors for Parkinson’s disease (PD) is essential for early diagnosis. Dating back to the 1920s, Parkinson’s disease and parkinsonism—an umbrella term that refers to motor symptoms found in Parkinson’s disease and also other conditions—have long been described in boxers.
Repetitive head impacts from tackle football can also have long-term neurological consequences like chronic traumatic encephalopathy (CTE). But research on the association between participation in tackle football and PD is limited.
In the largest study to describe the association between participation in football and the odds for having a reported diagnosis of PD, researchers from the BU CTE Center used a large online data set of people concerned for 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 sport 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 for 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 for having a reported diagnosis of parkinsonism or PD.
Football players who played at the college or professional level were at 2.93 increased odds for having a PD diagnosis compared with those who just played at the youth or high school level. Age of first exposure to football was not associated with odds for 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 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.
Funding: 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.CHAconsulted 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. MLAhas 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.
Association Between American Football Play and Parkinson’s Disease
Parkinsonism and Parkinson disease (PD) are known to result from repetitive head impacts from boxing. Repetitive head impacts from American football may also be associated with increased risk of neurodegenerative pathologies that cause parkinsonism, yet in vivo research on the association between football play and PD is scarce and limited by small samples and equivocal findings.
To evaluate the association between football participation and self-reported parkinsonism or PD diagnosis.
Design, Setting, and Participants
This cross-sectional study leveraged data from the online Fox Insight study. Participants completed online questionnaires and self-reported whether they currently had a diagnosis of Parkinson disease or parkinsonism by a physician or other health care professional. In November 2020, the Boston University Head Impact Exposure Assessment was launched for data collection on repetitive head impacts. Data used for this manuscript were obtained from the Fox Insight database on June 9, 2022. A total of 1875 men who endorsed playing any organized sport were included. Former athletes were divided into those who participated in football (n = 729 [38.9%]) and those who participated in other sports (reference group).
Self-reported participation in football, duration and level of football play, age at first exposure.
Main Outcomes and Measures
Logistic regression tested associations between PD status and history of football play, duration of football play, highest level played, and age at first exposure, controlling for age, education, history of diabetes or heart disease, body mass index, history of traumatic brain injury with loss of consciousness, and family history of PD.
In this sample of 1875 men (mean [SD] age, 67.69 [9.84] years) enriched for parkinsonism or PD (n = 1602 [85.4%]), 729 (38.9%) played football (mean [SD] duration, 4.35 [2.91] years). History of playing football was associated with higher odds of having a parkinsonism or PD diagnosis (odds ratio [OR], 1.61; 95% CI, 1.19-2.17). Among the entire sample, longer duration of play was associated with higher odds of having a parkinsonism or PD diagnosis (OR, 1.12; 95% CI, 1.06-1.19). Among football players, longer duration of football play (OR, 1.12; 95% CI, 1.02-1.23) and higher level of play (OR, 2.93; 95% CI, 1.28-6.73) were associated with higher odds of having parkinsonism or PD.
Conclusions and Relevance
In this cross-sectional study of participants enriched for PD, participation in football was associated with higher odds of having a reported parkinsonism or PD diagnosis.