Genetic data suggests higher levels of physical activity can protect against the risk of depression
A new research by a team of researchers from Massachusetts General Hospital (MGH) strongly support physical activity as a preventive measure for depression. Their report was published online in JAMA Psychiatry.
“Using genetic data, we found evidence that higher levels of physical activity may causally reduce risk for depression,” says lead author Karmel Choi, PhD, of the Psychiatric and Neurodevelopmental Genetics Unit in the MGH Center for Genomic Medicine.
The technique used in the study – Mendelian randomization – uses gene variants to study the effects of a non-genetic factor in a different approach from that of traditional research.
The objective readings from accelerometer capture things other than planned exercise – walking to work, climbing the stairs and mowing the lawn that participants may not recognize as physical activity
Gene variants from the results of large-scale genome-wide association studies (GWAS) that were conducted for physical activity in the U.K. Biobank and for depression by a global research consortium were used in this study. GWAS results for physical activity used two different measures: one based on 377,000 participants’ self-reports of physical activity and the other based on readings of motion-detecting sensors called accelerometers, worn on the wrists of more than 91,000 participants. The GWAS for depression was based on data from more than 143,000 participants with and without depression.
The results of the study indicated that accelerometer-based physical activity, but not self-reported activity, does appear to protect against the risk of depression. The objective readings from accelerometer capture things other than planned exercise – walking to work, climbing the stairs and mowing the lawn that participants may not recognize as physical activity. The analysis revealed no causal relationship in the other direction, between depression and physical activity.
“On average,” Choi says, “doing more physical activity appears to protect against developing depression. Any activity appears to be better than none; our rough calculations suggest that replacing sitting with 15 minutes of a heart-pumping activity like running, or with an hour of moderately vigorous activity, is enough to produce the average increase in accelerometer data that was linked to a lower depression risk.”