In a recent blog entry, entitled "Exercise is Good," I wrote about the many health benefits of exercise. As I mentioned, one area of research that has received increasing attention is the area of the cognitive benefits of exercise.
In this week's electronic edition of the Proceedings of the National Academy of Sciences, a group of investigators led by Kirk Erickson, from the University of Pittsburgh, report on an interesting study of 120 older adults (aged 55-80) who were followed for 1 year after beginning an exercise program. Half of the group was randomized to an exercise program that was moderate-intensity aerobic exercise (40 minutes of walking) for 3 days per week. The second half of the group was randomized to an exercise program that was non-aerobic--including only stretching or toning exercises for the same amount of time.
The participants had an MRI of the brain and a test of spatial memory before and after the 1-year study period.
The investigators found that both forms of exercise program were associated with an increase in the size of the patients' hippocampus--an area of the brain that is involved with memory. This increase was approximately 2% for the aerobic exercise group and 1.5% for the non-aerobic exercise group. We know from previous studies that this is an area of the brain that ordinarily shrinks with aging, so the new report offers encouraging news for aging adults.
The second finding from the study was that both forms of exercise program were associated with an improvement in the test of spatial memory. In this case, the aerobic exercise program did not provide any additional benefit over the non-aerobic program.
In interviews with the press, the investigators have characterized their findings as actually "turning back the clock" with the exercise program--not maintaining, but acutally improving patients' memory. Ongoing work is now focused on determining how long these changes in hippocampal size and improved memory will last.