Exercise and Dementia

Just a couple of months ago we told you about a randomized, controlled trial that indicated that omega-3 fatty acid supplements appear to have no effect on the rate of cognitive decline experienced by those over 70. They did note that omega-3s, like other vitamins, might have more of an effect when consumed as part of a food, and not in pill form, and that beginning treatment after the age of 70 might be too late (best to eat fish now!).

Recently, an article published in JAMA looked at the effect of physical activity on the risk of dementia or reduced cognitive function (2015;314(8):781-790). The study participants were 1,500 men and women between the ages of 70 and 89 who were at risk of losing mobility, but could walk at least 400 yards. They were randomly assigned to a physical activity program or to a more general health education program that included mild upper-body stretching.

For 24 months the participants assigned to the physical activity program attended physical activity classes (including strength training, balance, and flexibility exercises) twice per week at the lab, and committed to do the same activities at home 3-4 additional times per week.

Those assigned to the health education program attended health classes once weekly for the first 12 months and then at least once per month in the second year. These sessions varied in length and included guest speakers, demonstrations, field trips, and stretching and flexibility exercises.

At the start and end of the study, the participants responded to a battery of tests designed to measure their cognitive function and detect incipient dementia.

The authors found that there was no significant difference between the groups with respect to cognitive function or dementia, although those in the physical activity group who were over 80 and had more physical limitations did seem to experience improvement in their executive function, which has been described as the CEO of the brain - responsible for planning, managing time, and switching focus, among other things.

What this means for you

The authors admit that they can not rule out the idea that both interventions - physical activity or health classes - might have helped decrease the expected decline in cognitive function. That said, we do know that physical activity can be very beneficial for the elderly, keeping them more mobile and self-sufficient along with its other benefits. Keep exercising!

First posted: November 4, 2015