Medium amount of physical activity can lower risk of Parkinson’s
A new study by researchers at Karolinska Institutet shows that a medium amount of physical activity in daily life lowers the risk of Parkinson’s disease, compared to a very low level physical activity. The study, which is being published online in the journal Brain, followed 43,368 individuals in Sweden during a 12 year period.
The research team used the Swedish National March Cohort to analyse comprehensive information on physical activity of all kinds. They assessed household and commuting activity, occupational activity, leisure time exercise, and total daily physical activity according to data provided by 27,863 females and 15,505 males, as part of an extensive questionnaire. For the purpose of this study, physical activity was quantified into metabolic equivalent (MET) hours per day, based on estimated oxygen consumption associated with those activities.
All participants were free of Parkinson’s disease in October 1997, the start of the follow-up period. Study participants were followed from this baseline until date of diagnosis with Parkinson’s disease, date of death, date of emigration, or the end of the follow-up period in December 2010, whichever came first. In that time 286 cases of Parkinson’s disease were identified.
More than six hours per week
In the study’s multivariable-adjusted model, compared with participants who spent less than two hours per week on household and commuting activity, those who spent more than six hours per week on the same types of activities had a 43% lower risk of developing Parkinson’s disease. Compared with a low level of total physical activity, a medium level of total physical activity (a mean of 39.1 MET hours per day) was associated with a 45% lower Parkinson’s disease risk in males. In women the results were not as consistent, but the protective effect of physical activity in this group was supported when researchers summarized all available evidence from published prospective cohort studies. Leisure time exercise was not associated with Parkinson’s disease risk when analysed alone.
“One of many strengths of this study is that all information on physical activity and daily energy output was assessed before the disease occurrence, making recall bias and reverse causation less likely. The results show that a few hours spent at the gym do not have the protective effect that one would wish, but it is the physical activity in daily life that is of greater importance”, says Karin Wirdefeldt, researcher at Karolinska Institutet’s Department of Medical Epidemiology and Biostatistics, and Department of Clinical Neuroscience, who headed the study.“
First study-author is Fei Yang, doctoral student at the Department of Medical Epidemiology and Biostatistics. The work was funded by the Swedish Research Council, the Swedish Cancer Association, ICA Sweden, Ericsson, Karolinska Institutet and the Stockholm County Council.
Physical activity and risk of Parkinson’s disease in the Swedish National March Cohort
Fei Yang, Ylva Trolle Lagerros, Rino Bellocco, Hans-Olov Adami, Fang Fang, Nancy L. Pedersen, Karin Wirdefeldt
Brain, online 19th 2014, DOI: 10.1093/brain/awu323