Men who lack physical activity have a higher risk of developing Parkinson’s disease at some point in their lives, a systematic review has found. Importantly, findings revealed that even moderate exercise can be enough to counteract this effect.
The review, “Association of Levels of Physical Activity With Risk of Parkinson Disease,” was published in JAMA Network Open.
Parkinson’s disease, the second most prevalent neurodegenerative disease of the elderly (after Alzheimer’s disease), is characterized by the gradual loss of muscle control, sometimes accompanied by cognitive deficits.
The underlying causes of Parkinson’s disease are still poorly understood by scientists, but likely involve a combination of genetic and environmental risk factors. In the past 20 years, several prospective studies have focused on the effect of lifestyle factors, such as exercise, on Parkinson’s.
Although physical activity is known to decrease the risk of developing several conditions, including cardiovascular disease, stroke and diabetes, systematic studies addressing the impact of physical activity on Parkinson’s risk are few in number and often inconsistent regarding their methodology and data interpretation.
This systematic review focused on gathering data from previously published prospective studies to quantify the dose-response association between physical activity and Parkinson’s risk.
Following an initial period of literature research performed by two independent investigators, a total of eight prospective studies involving 544,336 participants — including 2,192 Parkinson’s patients with a median follow-up period of 12 years — focused on the relationship between physical activity and Parkinson’s risk, were included in the review.
Pooled data from all the studies showed that participants included in the highest category of total physical activity had a 29% lower risk of developing Parkinson’s compared to those who did not engage in any moderate-to-vigorous physical activity. Conversely, light physical activity was not linked to Parkinson’s risk.
Further subgroup analyses revealed that the relationship between physical activity and Parkinson’s risk was not influenced by geographic region, follow-up duration, population size, or study quality. They were affected, however, by gender, as the link between exercise and Parkinson’s risk was more robust among men, regardless of physical activity levels, compared to women.
Finally, the dose-response analysis showed that for each increase of 10 metabolic equivalents of task (MET) — a method to measure the energy cost of physical activities — of hours per week in total or moderate-to-vigorous physical activity, Parkinson’srisk in men decreased by 10% and 17%, respectively. This dose-response effect was not observed among women.
“[O]ur pooled analysis of more than half a million adults revealed that higher levels of physical activity —particularly moderate to vigorous activity — are associated with a lower risk of developing PD [Parkinson’s disease]. These benefits were significant among men, but were less robust among women,” researchers wrote.
“These findings may help guide physicians and health care policy makers in making recommendations and developing guidelines with respect to the degree of physical activity that can help reduce the risk of PD at both the individual level and the population level. More epidemiological studies with large sample size and detailed quantification of physical activity will help establish more precise information regarding this association,” they concluded.