Posted on Aug 30, 2013, 6 a.m.
Exercise may improve cognitive function in those at-risk for Alzheimer’s Disease, by improving the efficiency of brain activity associated with memory.
Population-wide surveys routinely identify memory loss leading to Alzheimer’s Disease as one of the greatest fears among aging Americans. While some memory loss is normal and to be expected as we age, a diagnosis of mild cognitive impairment (MCI) signals more substantial memory loss and a greater risk for Alzheimer’s Disease. J. Carson Smith, from the University of Maryland (Maryland, USA), and colleagues studied two groups of physically inactive older adults (ages 60 to 88 years), who were put on a 12-week exercise program that focused on regular treadmill walking and was guided by a personal trainer, meeting the WHO Guidelines of a weekly total of 150 minutes of moderate intensity exercise. Both groups – one which included adults with MCI and the other with healthy brain function – improved their cardiovascular fitness by about 10% at the end of the intervention. More notably, both groups also improved their memory performance and showed enhanced neural efficiency while engaged in memory retrieval tasks. Further, the team administered cognitive tests and conducted brain imaging before and after the 12-week exercise intervention. Brain scans taken after the exercise intervention showed a significant decrease in the intensity of brain activation in eleven brain regions while participants correctly identified famous names. The brain regions with improved efficiency corresponded to those involved in the pathology of Alzheimer’s disease, including the precuneus region, the temporal lobe, and the parahippocampal gyrus. The exercise intervention was found to be effective in improving word recall. The study authors conclude that: “These findings suggest exercise may improve neural efficiency during semantic memory retrieval in [mild cognitive impairment] and cognitively intact older adults, and may lead to improvement in cognitive function.”
J. Carson Smith, Kristy A. Nielson, Piero Antuono, Jeri-Annette Lyons, Ryan J. Hanson, Alissa M. Butts, et al. “Semantic Memory Functional MRI and Cognitive Function after Exercise Intervention in Mild Cognitive Impairment.” J Alzheimer’s Disease, 26 June 2013.