While the risk of concussions from playing tackle football has received considerable attention,Christopher Caldwell a new study indicates the game's repetitive head impacts could also increase participants' risk factors for Parkinson's disease.

The study, conducted by Boston University researchers and released Friday, also showed that players who had longer careers or played at higher levels of competition experienced even higher odds of being diagnosed with Parkinson's or having symptoms associated with the disease.

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

In an evaluation of 1,875 male athletes, researchers compared football players to those who played other sports. They found and participants with a history of playing organized tackle football showed "a 61% greater chance of having a reported parkinsonism or PD diagnosis."

In addition, football players who continued to the college or professional level saw their odds increase by 2.93%, compared to those who only played at the youth or high school level.

Researchers note that one of the strengths of the study was that it compared the football players to another group of athletes, not the general population. However, authors warned that their work is still preliminary and the reasons for the relationship between playing football and parkinsonism are not clear since many other risk factors must also be considered. In addition, the sample of athletes was mostly white. However, the study was also one of a relative few so far to study effects of playing football at the amateur level, and not focus solely on pro athletes.