Jacqueline Kerr, PhD, is an associate professor in the Department of Family & Preventive Medicine at the University of California at San Diego (UCSD). Her research focuses on physical activity and older adults, including community-based physical activity interventions.
ElderBranch interviewed Dr. Kerr to discuss her paper, “Objectively Measured Physical Activity Is Related to Cognitive Function in Older Adults,” which she wrote with Dr. Simon J. Marshall, Dr. Ruth E. Patterson, Catherine R. Marinac, Dr. Loki Natarajan, Kari Wasilenko, and Katie Crist of UCSD and Dr. Dori Rosenberg of the Group Health Research Institute.
What led you to research the relationship between physical activity and cognitive function in older adults? Why is this important? How does your current research augment other work in this area?
Most older adults are worried about cognitive functioning above other concerns. If we can demonstrate that physical activity is related to cognitive functioning, then we can help older adults preserve their mental capacity with exercise. This will also protect them against other diseases of aging.
If you ask older adults to recall their physical activity, their ability to recall is itself related to cognitive functioning. By using accelerometers, we can measure physical activity objectively and better assess the role of exercise in cognitive functioning.
Please describe your study. What were your in-going hypotheses?
We know that aerobic activity is related to cognitive functioning, partially because it increases blood flow to the brain. But not all older adults are able to exercise at high intensities. We therefore investigated whether lower intensities of physical activity were also related to cognitive functioning.
These data come from the baseline assessment of an intervention trial. In the future we hope to provide causal evidence that lifestyle activities like daily walking can improve or maintain cognitive functioning.
What were your findings?
Our study found that higher intensities of physical activity were related to better cognitive functioning.
What are the implications of your findings?
It may be that older adults do need to walk briskly to preserve their mental abilities. But our intervention trial results will provide more information on this and may find that increasing walking at lower intensities is also protective.
Would you give any specific recommendations to the directors of continuing care residential communities or to the residents themselves as a result of your findings?
For the specific cognitive benefits we tested here, residents would have to participate in activities of higher intensities if it were safe to do so. Walking at a faster pace, for example, might be important. However, given the overall health benefits of doing any activity versus none, it is important that continuing care retirement communities continue to provide exercise classes, aerobic equipment, and safe walking paths. If more vigorous activities threaten injury or falls, then they should not be recommended. Gradual increases in intensity in a safe environment – on a treadmill, for example – would be recommended.
Were there any notable limitations to your research? What are the next steps to further your work in this area?
As mentioned, this research employed only the baseline data from an intervention trial. The trial focuses on walking as a daily activity. Previous physical activity intervention studies for cognition have not been conducted in retirement communities, but rather in university laboratory environments. This type of exercise might not translate well to daily life. We hope to show that an increase in campus and neighborhood walking can be protective for cognitive functioning.