New research combining postmortem examination of brain tissue with testing during life has revealed what researchers believe to be an as-yet unexplained connection: higher levels of physical activity (PA) and motor skills seem to create a “cognitive reserve” that buoys cognitive performance during life, even in the presence of Alzheimer’s disease (AD), Lewy body disease, and other brain pathologies associated with dementia.
For the study, published ahead of print in Neurology, researchers examined brain tissue from 454 participants involved in the Rush Memory and Aging Project (MAP). The subjects participated in a battery of annual clinical assessments and agreed to brain donation at the time of death. The clinical tests included 21 cognitive assessments, an analysis of 10 motor abilities, and an estimation of total daily PA drawn from accelerometers worn constantly for 10 days (researchers in this study used only the first 7 days’ data).
The connection between physical activity (PA) and the slowing or prevention of cognitive decline in the elderly has been widely recognized, but an explanation of just how PA works on the brain’s chemistry has been more elusive. Now researchers in Germany believe they’ve isolated a chemical marker that helps identify PA’s neuroprotective effects.
The research project itself was fairly straightforward: split 53 cognitively healthy individuals 65 and older into 2 groups—the first of which received 3 half-hour supervised cycle training sessions per week for 12 weeks, and the second of which did not increase their PA—and then measure a host of factors associated with cognitive decline at the beginning and end of the 12-week training program. Researchers didn’t limit their investigation to chemical markers but also included evaluations of gray matter volume and cognitive performance tests. Results were published in Translational Psychiatry.