Older adults who took a brisk walk three times a week did better on memory tests and increased the size of their hippocampus, a portion of the brain involved with memory formation, researchers report. The findings suggest that loss of brain volume in old age can be delayed, and may even be reversible. Brain shrinkage is associated with memory impairment in the elderly. "We can change the brain in older adults," said lead study author Kirk Erickson, an assistant professor of psychology at the University of Pittsburgh.
"It's amazing that a one-year period of moderate exercise isn't just slowing down the atrophy, it's actually reversing it." For their the study, researchers from the University of Pittsburgh, University of Illinois, Rice University and Ohio State University divided 120 sedentary adults in their mid to late 60s, on average, into two groups: one group walked around a track for 40 minutes of aerobic exercise, three days a week, while the other group did stretching. Both groups performed better on a test of spatial memory. Spatial memory helps us to remember things like driving directions or where we left our keys.
But the groups differed in one important way. MRI brain scans showed that after a year on the exercise program, the aerobic exercise group's hippocampus was about 2 percent bigger than it was when they started, the equivalent to a reversal in age-related brain shrinkage of about one to two years, the researchers said. Those in the stretching group had a decrease of hippocampal volume of about 1.4 percent, the investigators found. Those who showed the greatest improvements in memory also showed the greatest increases in hippocampal volume, according to the study, published online Jan. 31 in the Proceedings of the National Academy of Sciences.