The hippocampus, which is the area of the brain damaged by Alzheimer's disease, plays an important role in forming long-term memories as well as in spatial navigation. Now, new evidence shows that exercise helps keep the hippocampus healthy.
Dr. J. Carson Smith, a kinesiology researcher in the University of the Maryland School of Public Health led the study that focus on the effect of exercise on the hippocampus. Over an 18 month period, Dr. Smith and his team tracked four groups of healthy older adults between the ages of 65 and 89 who had normal cognitive abilities.
Based on the presence or absence APOE-e4 allele, which is considered to be the genetic marker for younger onset Alzheimer's disease, the groups were classified both for low or high Alzheimer's risk and for low or high physical activity levels.
The result of studying these four groups showed that those at high genetic risk for Alzheimer's who did not exercise experienced a decrease in hippocampal volume over the 18-month period. The other groups, including those at high risk for Alzheimer's but who were physically active, maintained the volume of their hippocampus.
Dr. Smith says, "We know that the majority of people who carry the APOE-e4 allele will show substantial cognitive decline with age and may develop Alzheimer's disease, but many will not. So, there is reason to believe that there are other genetic and lifestyle factors at work. Our study provides additional evidence that exercise plays a protective role against cognitive decline and suggests the need for future research to investigate how physical activity may interact with genetics and decrease Alzheimer's risk."
Many people who carry the younger onset Alzheimer's gene feel that there's nothing they can do. This study holds out some hope. While there's no guarantee that regular exercise will prevent the disease, the fact that exercise appears to help a number of people with the gene avoid dementia certainly puts some power back into the hands of the individual.
This new information seems to circle back to the well known saying that what is good for the heart is good for the brain.
We don't need to run marathons in order to benefit from exercise. Being moderately active can do the trick. Brisk walking, bicycling, swimming and other exercise that many people find enjoyable may do far more to protect against Alzheimer's than has been previously thought.
University Of Maryland. (2014, April 23).Physical Activity Keeps Hippocampus Healthy in People at Risk for Alzheimer's Disease. Retrieved from http://www.sciencenewsline.com/summary/2014042316310038.html
MetLife Foundation Study (2011) Harris Poll. Retrieved from https://www.metlife.com/assets/cao/foundation/alzheimers-2011.pdf
University of Maryland (2013, July 30) Exercise May be the Best Medicine for Alzheimer's. Retrieved from http://www.umdrightnow.umd.edu/news/exercise-may-be-best-medicine-alzheimers