STEVE INSKEEP, host:
Exercise may have another bonus for people over 60. Michelle Trudeau reports on new research suggesting exercise can improve memory.
MICHELLE TRUDEAU: The hippocampus in your brain is small, smaller than your pinky, but it plays a big, essential role in memory. Now, as part of normal aging, the hippocampus shrinks. And this shrinkage accelerates as you grow older, foreshadowing memory problems. But scientists now know that the hippocampus can also grow, get bigger, not just in young people, but throughout our lifespan.
Dr. PETER SNYDER (Neuroscientist, Brown University): And there has been a huge amount of work over the past decade, mostly in animals but also in humans...
TRUDEAU: Says neuroscientist Peter Snyder from Brown University.
Dr. SNYDER: ...showing that new cells are created and new connections are made between cells, in this particular area of the brain in response to experience.
TRUDEAU: Snyder's interested in what we can do to maintain memory even as our brains age. He looks at diet, exercise, nutritional supplements, brain games.
Prof. SNYDER: Of all of these noninvasive ways of intervening, it is exercise that seems to have the most efficacy at this point - more so than nutritional supplements, vitamins and cognitive interventions.
TRUDEAU: Some of the most provocative evidence on the power of exercise comes from a study just published by neuroscientist Art Kramer at the University of Illinois documenting the impact of exercise on the growth of the hippocampus in a small group of elderly people over the course of one year. Here's Art Kramer:
Professor ART KRAMER (Neurology; Director, Beckman Institute, University of Illinois, Urbana-Champaign): The participants in our study were 120 very sedentary people. They're relatively healthy, but certainly couch potatoes would fit as a label.
Professor GREG STANTON (Management Information, University of Illinois, Urbana-Champaign): A semi-couch potato, let's put it that way.
TRUDEAU: Greg Stanton took part in the study. He's a 66-year-old semi-retired university professor. Stanton admits to not exercising regularly and knowing he should. And that's why he, along with 120 other men and women - 60 to 80 years - qualified for Art Kramer's two exercise groups.
Prof. KRAMER: One was the aerobic exercise group. Those were people who walked further and faster as time went on. And the others in our control group were in a toning, stretching and light-strengthening group.
Prof. STANTON: I went into the aerobic exercise group and basically it's walking a track in one of the gym facilities.
TRUDEAU: For about 40 minutes three times a week for a year.
Prof. STANTON: And the idea was to try to get in as many laps as possible and it turned out for me about three miles a session.
TRUDEAU: Now all the people in the study had brain MRIs done before the study and again a year later when the study ended. Researcher Art Kramer.
Prof. KRAMER: And what we found is that the individuals in the aerobic group showed increases in the volume of their hippocampus.
TRUDEAU: Two percent bigger after a year of aerobic exercise. For those in the control group, who did toning, stretching, light weight-lifting for the year, well, their hippocampus shrunk about one and a half percent, suggesting that not only did the aerobic exercise protect against normal shrinkage but also that new cells were added to the hippocampus.
Again, neuroscientist Peter Snyder.
Prof. SNYDER: To see a volume change in a structure of about two percent means that there really is very significant change going on in that region of the brain.
TRUDEAU: The growth of the hippocampus in the aerobic group was also associated with improvements in spatial memory - an important kind of memory that records information about your environment, like the layout of your neighborhood, or the interior of the grocery store. For this study, Kramer looked only at spatial memory, but in previous studies, verbal and other types of memory improved after an aerobic exercise program.
As for Greg Stanton, the 66-year-old semi-couch potato, he says he didn't notice any improvement in his memory.
Prof. STANTON: I always had difficulty remembering names and it's getting worse, actually.
TRUDEAU: But he did notice he had more physical stamina after the year of aerobic exercise. In spite of this, he still doesn't maintain a regular exercise regimen. The reason?
Prof. STANTON: I have less time than I think I should have.
(Soundbite of laughter)
TRUDEAU: Like many of us, he knows exercise is good for him, but he's just too busy to do it.
For NPR News, I'm Michelle Trudeau.
INSKEEP: And that's Your Health for this Monday morning.
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