Aerobic exercise shown to improve memory in those at risk of dementia

The results of a year-long trial led by researchers at UT Southwestern have homed in on how aerobic exercise can improve memory in older subjects with mild cognitive impairment. The findings suggest it is never too late to start exercising as aerobic activity improves blood flow to regions of the brain associated with memory.

“We’ve shown that even when your memory starts to fade, you can still do something about it by adding aerobic exercise to your lifestyle,” explains lead author on the new study, Binu Thomas.

The study focused on the long-term changes to cerebral blood flow stemming from aerobic exercise in subjects already presenting with age-related mild cognitive impairment. Thirty subjects – with an average age of 66, no reporting of regular exercise, and signs of memory impairment – were split into two groups.

One group was tasked with completing several aerobic exercise sessions per week for 12 months, while the other group performed stretch and balance sessions designed to strengthen upper and lower body while keeping heart rates low. At the beginning and end of the year-long study MRI scans measured cerebral blood flow in all participants.

After 12 months the aerobic exercise group displayed increased cerebral blood flow to the anterior cingulate cortex and adjacent prefrontal cortex, relative to the stretching group. Memory tests conducted at the beginning and end of the study also revealed a 47-percent improvement in the aerobic group, compared to only minimal improvements in the stretching group. The study notes a direct correlation between improvement on the memory test scores and increases in cerebral blood flow to these key brain regions.

“Cerebral blood flow is a part of the puzzle, and we need to continue piecing it together,” notes Thomas. “But we’ve seen enough data to know that starting a fitness program can have lifelong benefits for our brains as well as our hearts.”

The cohort studied was indeed small, however, the results are in line with a large volume of prior research affirming the value of exercise in maintaining cognitive abilities in older age. Aerobic exercise seems to confer the greatest cognitive protections, especially in those most at risk of Alzheimer’s disease.

The researchers note the cohort recruited in the study all reported little to no regular exercise before the trial. The novelty of this particular trial is that it offers an indication that aerobic exercise can confer cognitive benefits even when started at an advanced age, after memory decline has already commenced, and those cognitive benefits may be mediated specifically by improved blood flow to specific regions of the brain.

“Perhaps we can one day develop a drug or procedure that safely targets blood flow into these brain regions,” says Binu Thomas, Ph.D., a UT Southwestern senior research scientist in neuroimaging. “But we’re just getting started with exploring the right combination of strategies to help prevent or delay symptoms of Alzheimer’s disease. There’s much more to understand about the brain and aging.”

The new study was published in The Journal of Alzheimer’s Disease.

Source: UT Southwestern

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