Exercise In Late Adulthood Improves Memory, Researchers Say
Regular aerobic exercise during late adulthood can help improve memory and decrease one’s risk of dementia, according to a study published Monday in the Proceedings of the National Academy of Sciences.
Previous studies show that exercise can lead to new cell growth in regions of the brain, boosting function, but whether similar growth takes place in the hippocampus, a part of the brain involved in memory that tends to decline in old age, remained unclear.
To help answer this question, researchers put 120 sedentary adults in their 60s to work – half of the group took to the track where they walked for 40 minutes, three days a week, while the others participated in a lower intensity stretching regimen. Both groups participated in the program for one year.
Although hippocampal regions of two groups were similar at the beginning of the exercise program, MRI scans revealed that after one year the hippocami of walkers grew by about 2 percent whereas seniors exposed only to stretching activities experienced a shrinkage in this same region of about 1.4 percent over the same period.
Additional analysis revealed that the greater the fitness progress made by the adults over the course of the trial, the greater the growth in the hippocampus. Blood tests also confirmed that the walkers had higher levels of the protein BDNF, known to be involved in the growth of new brain cells, corresponded with the changes in hippocampal volume.
“We think of the atrophy of the hippocampus in later life as almost inevitable,” with an estimated 1 to 2 percent lost annually, Kirk Erickson, professor of psychology at the University of Pittsburgh and lead author of the study said in a university press release. “But we’ve shown that even moderate exercise for one year can increase the size of that structure. The brain at that stage remains modifiable.”
The participants were also given a spatial memory test before, during and after the exercise period. Both groups became faster at responding to the test and more accurate between the first and last testing sessions for aerobic exercise and stretching. However, researchers did find that participants who had larger hippocampi at the start and completion of the program had better performances in the memory tests, leading them to believe that growth in the hippocampus resulting from exercise “should translate into improved memory function.”
“The results of our study are particularly interesting in that they suggest that even modest amounts of exercise by sedentary older adults can lead to substantial improvements in memory and brain health,” Art Kramer, director of the Beckman Institute at the University of Illinois and the senior author said, according to the press release. “Such improvements have important implications for the health of our citizens and the expanding population of older adults worldwide.”
