The cognitive benefits of aerobic exercise are well established with trained individuals demonstrating decreased risk of mental health disorders, including anxiety and depression, and improvements of cognitive function and memory compared to their sedentary peers. More recent research has documented daily physical activity is also associated with decreased risk of dementia in aging adults even in those with pathology on brain imaging such as neurofibrillary tangles and amyloid plaques. Both of these brain pathologies are associated with dementia and alzheimer’s disease. In addition, previous research has shown moderate walking, 45 minutes/day for 3 days/week, actually increased brain volume among particpants. Another recent study suggests even general activity such as light housework and gardening may be enough to improve brain health within this population.
Buchman and colleagues examined the impact of daily movement (gardening, housework, exercise) on cognitive and motor function, as well as, brain health (Neurology. 2019). Researchers performed a well designed trial of over 450 aging adults (> 70 y.o.) and monitored their mental and physical function, as well as, daily activity each year over a 20 year period. Of these adults, 191 demonstrated clinical signs of dementia during the study period. In addition, researchers studied the donated brains of these individuals after their deaths to determine the presence of brain abnormalities and pathology.
Consistent with prior research, more active participants demonstrates higher scores on cognitive, memory, and physical tests. Interestingly, these results held up even among individuals with brain pathologies including neurofibrillary tangles and amyloid plaques. Although all of these individuals could have been diagnosed with neurological diseases such as Alzheimer’s, 30% tested normally on cognitive function tests at the time of their deaths. Authors suggested exercise and activity may have a protective effect on brain health (symptoms) even in the presence of brain changes (signs of dementia). Authors recommend more research in this area to determine if there is a cause and effect relationship between these two factors.