High levels of moderate to vigorous physical activity appear to be protective against the development of Parkinson’s disease in later life.
A systematic review and meta-analysis of eight prospective studies comprising more than half a million adults found an inverse, dose-response relationship between physical activity and Parkinson’s disease.
Studies included the US Nurses’ Health Study, Health Professional’s Follow-Up Study and Harvard Alumni Health Study.
The relationship was significant for total and moderate to vigorous physical activity but not lower levels of physical activity.
“Specifically, participants in this highest category of activity had a 29% lower risk of PD than those who reported no moderate to vigorous activity,” the study authors said.
A dose-response analysis showed an increase of 10 metabolic equivalent of task-hours per week in total physical activity decreased the risk of Parkinson’s disease by 10% in men and 9% in mixed-sex populations.
Overall, the study found the relationship between physical activity and Parkinson’s disease was significant in men but not in women.
A time-lag analysis found no suggestion the association could be explained by reverse causality such as decreased physical activity in early Parkinson’s disease.
The study concluded that their 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’.
An Invited Commentary published in JAMA Open said the findings were supported by another recent cohort study, which found high physical fitness was associated with a lower incidence of Parkinson’s disease.
It added that the strength of the association, consistency of findings, temporality, biological gradients and biological plausibility met the criteria for causality.
“Based on the results summarised in the article by Fang et al, it seems clear that protection against PD can be added to the list of likely benefits of physical activity.”
And there was the possibility that physical activity could also slow the progression of disease.
“Because the pathology of PD is characterized by progressive dopaminergic deficiency and selective loss of neurons in the substantia nigra, factors which reduce the risk of developing PD may also slow disease progression after diagnosis, as has been found for caffeine consumption and lower serum urate levels.”
The author also added that it was premature to exclude the possibility that the inverse association between physical activity and Parkinson’s disease did not also apply to women.