Playing tackle football may increase the risk of Parkinson’s disease

In the largest study describing the link between participation in football and the likelihood of a reported diagnosis of Parkinson’s, Researchers at the BU CTE Center used a large online dataset of people concerned about having Parkinson’s and found that participants with a history of playing organized football had a 61% greater chance of having a reported diagnosis of Parkinson’s or Parkinson’s.

In this study, the researchers evaluated 1,875 sports participants: 729 men who played football, mainly at the amateur level, and 1,146 men who played non-soccer sports and who served as a control group. Participants took part in Fox Insight, a longitudinal online study of people with and without Parkinson’s, sponsored by the Michael J. Fox Foundation for Parkinson’s Research.

Notably, researchers found a link between playing football and a greater chance of receiving a diagnosis of parkinsonism or Parkinson’s, even after taking into account known risk factors for Parkinson’s disease. Additionally, the data revealed that players with longer careers and who played at higher levels of competition were more likely to have a reported diagnosis of parkinsonism or Parkinson’s. Football players who played at the college or professional level had a 2.93 higher odds of receiving a PD diagnosis compared to those who just played at the youth or high school level. The age of first exposure to football was not associated with the likelihood of having a reported parkinsonism or Parkinson’s diagnosis.

“Playing tackle football could be a contributing risk factor for Parkinson’s disease, especially 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 neurological disorders later in life, meaning that 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 notable strength of the study. Furthermore, most participants played tackle football exclusively at the amateur level, which contrasts with most research to date that has focused on professional athletes.

“Previous research has focused on the association between American football and the risk of CTE. But similar to what has been historically seen in boxers, American football could also influence the risk of other neurodegenerative disorders such as Parkinson’s disease,” 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 who were enriched for having Parkinson’s disease and who were largely white, limiting the generalizability of the findings. Parkinson’s diagnosis was also self-reported by participants via online assessments, but no objective in-person evaluations were conducted.

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 the data used in this manuscript. Grant funding also came from NINDS (U54NS115266; K23NS102399).