The study involved 454 older individuals of which 191 had dementia and 263 did not; those who were more active had better memory and thinking skills than those who were more sedentary, which was observed even in participants who displayed physical signs of dementia.
Participants agreed to donate their brains for research upon death which occurred at an average age of 91, and underwent yearly physical exams as well as thinking and memory testing over a 20 year period.
Wrist worn accelerometers were given to each participant to monitor their physical activity 24/7 which ranged from walking around to engaging in more vigorous exercise; analysis of participant average daily scores showed more daily movements were associated with improved thinking and memory skills compared with less movement. Those who demonstrated better motor skills scored higher on memory and thinking tests.
According to analysis each standard deviation increase in physical activity was associated with a 31% decreased likelihood of developing dementia; and each standard deviation increase in motor ability was associated with a 55% decreased likelihood of developing dementia.
Association between increased physical activity and better test scores remained even after adjusting for presence of biomarkers for Alzheimer’s disease and brain lesion severity after post mortem analysis.
Dr. Aron Buchman states a more active lifestyle may have a protective effect on the brain, and exercise is an inexpensive way to improve health; but this study does not provide evidence for cause and effect and it may be possible that as people lose memory and thinking skills they reduce physical activity levels, more studies are needed to determine this.
