Older people who would like to stay sharp can take one simple step: keep moving! Research from Rush University Medical Center suggests that physical activity can reduce elders’ risk of dementia (Buchman et al, Neurology, online Jan. 16, 2019).
How Was the Research on Physical Activity and Cognitive Function Conducted?
The investigators examined 454 older individuals every year for as long as 20 years. The volunteers took cognitive tests and had annual physical exams. They also agreed to donate their brains for examination upon their deaths.
It is more complicated to measure physical activity, other than relying on what people say they are doing. (That doesn’t always correspond well to what they actually do.) To determine the volunteers’ activity levels, each participant wore an accelerometer for seven days during the study. This is a device worn like a wristwatch that measures all movements. These may range from small actions such as walking from one room to another to much larger actions such as a vigorous exercise routine. In addition, the volunteers completed 10 supervised motor performance tests as part of the testing regimen.
What Was the Relationship Between Physical Activity and Dementia?
Some of the study subjects had dementia, while the others did not. The accelerometer picked up differences between these two groups. Those with dementia made an average of 130,000 movements daily, as counted by the accelerometer. That may sound like a lot, but the people who were in better cognitive shape had an average of 180,000 movements daily. Overall, people with better motor skills also scored better on measures of memory and thinking.
Volunteers who moved more during the day were more likely to be thinking clearly and remembering things better. Physical activity and motor skills accounted for 8 percent of the differences in cognitive test scores. Brain autopsies showed that even people with signs of Alzheimer disease did better than expected if they maintained strong physical activity to the end of their lives.
The scientists concluded:
“Physical activity in older adults may provide cognitive reserve to maintain function independent of the accumulation of diverse brain pathologies. Further studies are needed to identify the molecular mechanisms underlying this potential reserve and to ensure the causal effects of physical activity.”
This is not the first study to demonstrate the cognitive benefits of physical activity. A recent study showed that seniors in an active exercise program improved their executive function. Of course, there is also the more immediate reward: taking time to play just makes you feel good!