Brain size increases in older adults who exercise

There is now conclusive evidence that hitherto sedentary older adults can see improvements in memory after just one year of moderate exercise.

The exercise that got the older folk up and moving is just moderate walking three times a week at 40 minutes a time. It has been shown that regular walking shows an increase in the size of the hippocampus with improvement in memory after just one year.

Head of research Kirk Erickson, PhD, professor of psychology at the University of Pittsburgh in Pennsylvania, said in an interview with Medscape Medical News: "There are two very important messages to take home from this study. The first is that the brain remains modifiable until late adulthood, and this gives us a lot of promise for interventions and treatments that could prevent or delay or even reverse atrophy of the brain. The second major message is that it's never too late to start exercising."

The study involved 60 adults aged 60 to 80 who had done only 30 minutes or less of weekly moderate exercise. They were started on a programme of brisk walking as part of aerobic training. The control group consisted of 60 sedentary adults who were limited to just doing stretching and toning exercise.

Dr Erickson explained: "They were fairly inactive individuals, which is unfortunately very common in society, but nonetheless, we brought them in and started them walking. We first started them walking 10 to 15 minutes at a time because they were not used to exercise, and eventually we progressed them to about 40 minutes a day for 3 days a week and that lasted for a year."

Trained exercise experts monitored their heart rate and level of exertion. They all had a certain amount of brain atrophy although this had not developed into dementia.

MRI were used to take high resolution detailed images of their brains and this was done three times - once before the start of the programme, then after six months and finally after the programme was completed. Concurrently, the participants were given memory tests measuring their spatial memory.

Those who exercised aerobically displayed an increase in the size of their hippocampus. Their left side increased by 2.12% and their right by 1.97%, while the control group showed 1.40% and 1.43% decline in the left and right hippocampus, respectively.

Dr Erickson observed: "Up to now, we have never demonstrated that if we take people who are previously sedentary and give them exercise that we can actually increase the size of this region of the brain."

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