February 1, 2011

Brisk Walking Improves Memory In Older Adults

A part of the brain involved in memory grew in size among adults aged 55 and older who undertook moderate physical exercise for one year, according to a new study published Monday in the Proceedings of the National Academy of Sciences.

The research supports previous findings that aerobic exercise reduces brain atrophy in early-stage Alzheimer's patients, and that regular walking helps improve performance on mental tests among older people with memory problems.

The current study found that one year of brisk walking increased the size of the brain's hippocampus in older adults, leading to an improvement in spatial memory. 

The hippocampus is a region of the brain involved in all forms of 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," said Art Kramer, director of the Beckman Institute at the University of Illinois and the study's senior author.

"Such improvements have important implications for the health of our citizens and the expanding population of older adults worldwide."

The researchers from the University of Pittsburgh, University of Illinois, Rice University, and Ohio State University recruited 120 sedentary older adults without dementia, and randomly assigned them to one of two groups.  The first group began an exercise program of walking around a track for 40 minutes a day, three days a week, while the second group was limited to just stretching and toning exercises.

The results showed that those in the aerobic exercise group exhibited an increase in volume of the left and right hippocampus of 2.12 percent and 1.97 percent, respectively, the researchers said.

The same regions of the brain in those who performed only stretching exercises decreased in volume by 1.40 and 1.43 percent, respectively.

"We think of the atrophy of the hippocampus in later life as almost inevitable," said Kirk Erickson, professor of psychology at the University of Pittsburgh and the study's lead author.

"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."


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