Active Voice: A Little Physical Activity Can Offset Cognitive Decline in Older Adults
By Wenfei Zhu, Ph.D., and Steven P. Hooker, Ph.D., FACSM, FNAK
Wenfei Zhu, Ph.D., is an assistant professor in the College of Physical Education at Shaanxi Normal University, Xi'an China. She received her Ph.D. from College of Health Solutions at Arizona State University in Phoenix, Arizona. Her research interests include physical activity measurements and chronic disease prevention in older adults. She presently is funded by the Humanities and Social Science Program of the Ministry of Education of China and Fundamental Research Funds for the Central Universities in China.
Steven Hooker, Ph.D., FACSM, FNAK, is a professor in the School of Nutrition and Health Promotion and associate dean of research in the College of Health Solutions at Arizona State University. Dr. Hooker’s research focuses on creating and evaluating gender-specific and culturally-tailored healthy lifestyle interventions for racial/ethnic minority men.
This commentary presents the authors’ views on the topic of their research article that they authored with colleagues and which appeared in the January 2017 issue of Medicine & Science in Sports & Exercise® (MSSE).
The worldwide aging of the population is associated with varying health-related challenges, including increased rates of cognitive impairment. This corresponds to diminished functional capacity and independence among seniors, and escalates to include financial and emotional burdens. Therefore, it is incumbent on society to devise and deliver interventions to help adults sustain their cognitive health in later life.
Physical activity (PA) is known to provide benefits for cognitive health and quality of life among older adults. This has resulted in national guidelines, such as the Physical Activity Guidelines for Americans that specifically encourage regular PA among older adults to reduce the risk of cognitive decline. Some of the existing evidence derives from longitudinal studies employing self-reported PA assessments. Objective PA measures, such as those from an accelerometer, are increasingly used to overcome certain limitations of self-report measures. Additionally, important differences exist in PA levels across racial/ethnic minorities groups in the population that are more likely to be misclassified by self-report questions. Despite these important limitations, few investigations are based on studies that include a large proportion of minorities. Thus, a better understanding of the relationship between objectively measured PA and cognition in racial/ethnic groups would add substantially to our knowledge of how best to promote healthy cognitive aging.
In our study, as published in the January 2017 issue of MSSE, older adults were recruited from the REasons for Geographic and Racial Differences in Stroke (REGARDS) study. Research-grade accelerometers provided estimates of moderate-to-vigorous PA (MVPA), light PA and sedentary time. Incidence of cognitive impairment and measures of executive function and memory were obtained during an average follow-up of three years among 6,452 older adults (55 percent women; 31 percent black).
Our results indicated even a minor increase in MVPA (i.e., 3-5 minutes) was associated with a significant (36 percent, or greater) decrease in incident cognitive impairment and greater maintenance of executive function and memory. Higher MVPA was independently associated with a 39-47 percent lower risk of cognitive impairment and better maintenance of memory and executive function in white adults. Higher MVPA also was significantly associated with better maintenance of memory performance in black adults. These findings confirm previous conclusions based on self-report PA and recommendations to help maintain optimal cognitive function during aging with MVPA. We call for more investigations on the potential impact of objectively-measured patterns of PA, bouts of sedentary behaviors and light PA on cognition in diverse older adults and studies exploring the underlying physiologic mechanisms.
Although future studies will help refine PA and sedentary behavior recommendations for older adults, we encourage aging-focused researchers and practitioners to develop more innovative approaches to promote PA and brain health. For now, our current analysis indicates that we can more confidently suggest that even a small dose of daily free-living MVPA (28 minutes per week) is significantly associated with maintenance of cognitive performance. Some existing policy, environmental and community initiatives that can help in this regard and deserve support and further dissemination include the Age-friendly Cities initiative directed by the World Health Organization and the American Association of Retired Persons, Safe Routes for Seniors program as instituted in New York City, Chicago and San Francisco, and SilverSneakers fitness program supported by dozens of health plans in the U.S.