New research suggests that American football players have higher odds of developing Parkinson's disease or Parkinsonism — especially if they have participated in the sport for several years.
Parkinson's disease (PD) is a neurodegenerative condition that impacts nerve cells in the brain. It causes movement-related symptoms such as tremors, problems with walking, and stiffness. PD can also influence mood, sleep, and cognitive function. In contrast, parkinsonism is an umbrella term for Parkinson's-like symptoms associated with other neurological disorders.
Males, people with a family history of PD, and those over 65 are more likely to experience the condition. Moreover, traumatic brain injury (TBI) is another risk factor for PD, and those involved in contact sports, such as American football, are at risk of experiencing this type of head injury.
Current research focusing on the long-term neurological effects of football has primarily centered on professional football players. However, more people play the game during their high school and college years, which makes understanding the possible long-term effects critical.
In a new study published on August 11 in JAMA Network Open, researchers investigated the possible associations between football participation and Parkinsonism or PD in 1,875 men.
The participants completed online questionnaires, self-reporting whether they played football, at what age they started playing, and how long they were involved in the sport. They also reported what level of football they reached, such as high school or college level.
The questionnaire also asked the participants whether they were diagnosed with Parkinson's Disease or Parkinsonism.
Armed with the self-reported data, the researchers divided the participants into two groups — those who played football and those who participated in other sports. The scientists identified a total of 729 participants who played football.
Among the former players, 575 played football at the grade school or high school level, 118 participated at the college level, and 5 played pro or semi-pro football. Moreover, the participants played an average of 4.35 seasons.
After adjusting for factors that could impact the results, such as previous TBI with loss of consciousness, or a family history of PD, the scientists found that playing football was associated with higher odds of having a self-reported Parkinsonism or PD diagnosis.
Specifically, nearly 89% of football players in the study reported having Parkinsonism or Parkinson's disease.
In addition, playing football for longer lengths of time and engaging in a higher level of play were also linked to higher odds of having Parkinsonism or PD.
The participants that self-reported a Parkinsonism or PD diagnosis were older and had a lower BMI and education level. They were also less likely to have a family history of the condition.
Study authors say the associations between football participation and Parkinson's found in the study may be related to repetitive head impacts that can occur during practices and games. Though more research is needed, the authors suggest that football participation might be a risk factor for developing the disease.
Still, there are several limitations to the study. For example, 98% of the participants were white, so it's unclear if the findings can be generalized to football players of other racial and ethnic groups.
Moreover, the study gathered data online, and participants self-reported their football histories and PD diagnoses, which could have skewed the results. In addition, the study authors note that people at risk for PD or concerned about the condition are more likely to participate in studies of this type.
The authors conclude, "Prospective research among community-based samples that objectively evaluate Parkinsonism and PD in former American football players across different levels of play will clarify the observed associations."
- Parkinson's Foundation. Parkinson's Disease vs. Parkinsonism.
- JAMA Network Open. American Football Play and Parkinson Disease Among Men.