While some memory loss is normal and to be expected as we age, a diagnosis of Mild Cognitive Impairment, or MCI, signals more substantial memory loss and a greater risk for Alzheimer's, for which there currently is no cure.
The study, led by Dr J Carson Smith, assistant professor in the Department of Kinesiology, provides new hope for those diagnosed with MCI. It is the first to show that an exercise intervention with older adults with Mild Cognitive Impairment (average age 78) improved not only memory recall, but also brain function, as measured by functional neuroimaging (via MRI).
"We found that after 12 weeks of being on a moderate exercise programme, study participants improved their neural efficiency - basically they were using fewer neural resources to perform the same memory task," said Smith.
"No study has shown that a drug can do what we showed is possible with exercise," Smith said. Two groups of physically inactive older adults (ranging from 60-88 years old) were put on a 12-week exercise programme that focused on regular treadmill walking and was guided by a personal trainer.
Both groups - one which included adults with MCI and the other with healthy brain function - improved their cardiovascular fitness by about 10 percent 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.
One of the first observable symptoms of Alzheimer's disease is the inability to remember familiar names. Smith and colleagues had participants identify famous names and measured their brain activation while engaged in correctly recognizing a name.
Tests and imaging were performed both 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 11 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 study was published in the Journal of Alzheimer's Disease.