Parkinson disease (PD) is the second most common neurodegenerative disease affecting approximately 10 million people around the world. So far, the etiology of PD is poorly understood, and 90% PD cases have no identifiable genetic cause. What’s worse, there have been few therapeutic advances for people with PD in the past decades. Thanks to growing prospective longitudinal studies, researchers have found that a number of lifestyle factors likely modify the risk of developing PD.
In this article, Prof. Wang’s research team performed a meta-analysis of prospective studies to determine whether there is evidence of a quantitative dose-response association between physical activity and risk of PD. The analysis included 8 prospective studies with a total of 544336 adults followed up for an average of 12 years, with more than 2100 PD cases. The results showed a significantly reduced risk of PD tied to the highest levels of either total physical activity or moderate-to-vigorous physical activity, with stronger associations among men than women. However, light physical activity was not tied to PD risk. In addition, each 10 metabolic equivalent of task-hours per week increase in total activity reduced PD risk by 10% and by 17% in those who engaged in total and moderate-to-vigorous physical activity.
These benefits of physical activity were constant in subgroup analyses based on follow-up duration, geographical region, sample size and study quality. This study provided compelling evidence that physical activity, particularly moderate-to-vigorous physical activity, was associated with a significantly reduced risk of developing PD.
In a related editorial, Lorene M. Nelson, PhD, of the department of health research and policy at Stanford University School of Medicine, wrote: “The article by Fang et al is an excellent example showing meta-analysis in its best role”. According to Dr. Nelson, “it seems clear that protection against PD can be added to the list of likely benefits of physical activity”.
