Walking three times a week may improve memory in older adults and help prevent mental decline as people age, a study by U.S. researchers found.
The study of adults ages 55 and older found a 2 percent expansion of the hippocampus, the brain’s memory processor that can shrink during middle age, in those who walked 40 minutes, three times a week, for a year. The findings are reported today in the Proceedings of the National Academy of Sciences.
As the number of people older than age 65 increases, more low-cost preventions and treatments to slow mental decline are needed, the researchers said. The study shows the typical, age-related shrinkage of the hippocampus isn’t “inevitable” and can be reversed with moderate exercise, they said.
“You can think of this improvement as winding back the clock about two years in brain health,” said Arthur Kramer, director of the Beckman Institute at the University of Illinois at Urbana-Champaign and a professor of neuroscience and psychology, in a Jan. 28 telephone interview. “It really is surprising that such modest changes in somebody’s lifestyle can have such dramatic benefits. You don’t have to be an athlete to reap these benefits.”
Researchers included 120 people from the ages of 55 to 80 who were healthy yet didn’t exercise regularly. They were divided into a group that walked three days a week and another that engaged in stretching and toning. The walkers averaged about 15 minutes a mile by the study’s end, Kramer said.
Those who only engaged in toning and stretching saw the hippocampus decline 1.4 percent, the study found.
More research is needed to determine what happens to the brain once exercise stops and what benefits occur for people who exercise more frequently and at higher rates of intensity than those in the study, he said.