For years, health professionals have been preaching about the importance of exercise to cardiovascular and overall health. “Whatever is good for the heart is good for the brain.” The latest study of older adults at increased risk for Alzheimer’s disease is the first evidence that physical activity may protect against cognitive decline and the onset of dementia symptoms in people who carry the genetic marker for Alzheimer’s.
The hippocampus, the brain region responsible for memory and spatial orientation, normally loses some volume as we age. But overtime, people with an increased genetic risk for Alzheimer’s disease experience greater atrophy in that area of the brain, which means they experience greater memory loss and cognitive dysfunction.
The good news is that Dr. J. Carson Smith, a kinesiology researcher in the University of Maryland School of Public Health, and his colleagues found clear evidence that being physically active has the potential to help protect the hippocampus in people at increased risk for Alzheimer’s disease. This is especially significant because if you know that exercise can help delay the onset of the disease and if you engage in an exercise regimen it could extend your longevity and ability to take care of yourself. This, in turn, would reduce the financial burden of needing a caregiver and other medical intervention.
Dr. Smith and colleagues tracked four groups of healthy older adults ages 65-89, who had normal cognitive abilities, over an 18-month period and measured the volume of their hippocampus (using structural magnetic resonance imaging or MRI) at the beginning and end of that time period. The groups were classified both for low or high Alzheimer's risk (based on the absence or presence of the apolipoprotein E epsilon 4 allele) and for low or high physical activity levels.
Of all four groups studied, only those at high genetic risk for Alzheimer's who did not exercise experienced a decrease in hippocampal volume (3%) over the 18-month period. All other groups, including those at high risk for Alzheimer's but who were physically active, maintained the volume of their hippocampus.
Whether you are at high risk for Alzheimer’s or not, it’s never too late or too early to start a daily exercise regimen. If you are sedentary start walking 30 minutes three days a walk, and go from there. Park your car at the opposite end of the parking lot, from where you need to go. Get a walking buddy, or get a dog. Whatever you do, be serious about being physically active. It could have a huge impact on your life and the lives of your loved ones.
J. Carson Smith, Kristy A. Nielson, John L. Woodard, Michael Seidenberg, Sally Durgerian, Kathleen E. Hazlett, Christina M. Figueroa, Cassandra C. Kandah, Christina D. Kay, Monica A. Matthews, Stephen M. Rao. Physical activity reduces hippocampal atrophy in elders at genetic risk for Alzheimer's disease. Frontiers in Aging Neuroscience, 2014; 6 DOI: 10.3389/fnagi.2014.00061