Exercise can increase brain connectivity related to memory and may help older adults at risk of Alzheimer’s disease, according to a new study published in the Journal of Alzheimer’s Disease led by J. Carson Smith at the University of Maryland.
Exercise has been shown to have neuroprotective effects in the hippocampus, a key brain region for memory that is among the first affected by Alzheimer’s disease.
Dr. Smith, a professor of kinesiology in the UMD School of Public Health, and his research team recruited older adults at risk of Alzheimer’s disease, as well as a control group with normal cognitive functioning, for an exercise intervention aimed at understanding how changes in hippocampal function may relate to memory performance.
The study participants took two standardized memory tests and separately had MRI brain imaging performed before and after they participated in the 12-week exercise program, which involved moderately intense walking four times a week.
“The cognitive tests rely on the hippocampus of the brain, which is central to episodic memory and memory recall. We know that Alzheimer’s attacks the hippocampus very early in the disease process and that exercise improves the hippocampal function,” said Dr. Smith.
“We used the MRI to measure the functional connectivity in the brain. We saw that both groups showed a significant increase in connectivity between the hippocampus and other regions of the brain after 12 weeks. These regions, which form a neural network for memory, were more in sync.”
The team also found that the participants with mild cognitive impairment (or MCI, the precursor to developing Alzheimer’s and other dementias) improved in their performance on the memory task tests after 12 weeks. The improvement in connectivity, measured via fMRI, was correlated to their ability to recall details of the stories in the memory tests, which was not the case with the cognitively normal participants.
“Although exercise did not completely cure their cognitive impairment, the fact that exercise can reverse the downward spiral of cognitive function in the MCI group indicates improved brain function is still possible for those with MCI ,” said Dr. Smith.
These results are encouraging because it suggests that the benefits of exercise do not require you to become a marathon runner. Moderate intensity walking four days a week or more can improve your cognitive function and increase communication in your brain.”