Just as football season kicks off, a new study shows that playing tackle football might raise the risk for Parkinson’s disease.

Researchers from the BU CTE Center found that people with a history of playing organized tackle football had a 61% increased chance of having a reported diagnosis for Parkinson’s disease or parkinsonism — motor symptoms found in Parkinson’s and other conditions.

Repetitive head impacts from tackle football have been tied to long-term neurological consequences, like chronic traumatic encephalopathy (CTE). But there hasn’t been much research on the link between tackle football and Parkinson’s disease (PD).

“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 corresponding study author Michael Alosco, associate professor of neurology at Boston University Chobanian and Avedisian School of Medicine.

“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,” Alosco added.

In this study, the researchers looked at 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 in the study, researchers found a link between playing football and increased odds for having a PD or parkinsonism diagnosis, even after accounting for known risk factors for PD.

The study also 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.

“Previous research has focused on the association between American football and risk for CTE,” said Hannah Bruce, first study author and research specialist at Boston University Chobanian and Avedisian School of Medicine. “However, similar to what has historically been seen in boxers, American football might also affect risk for other neurodegenerative conditions such as PD.”