A fit body can increase the chances of a fit mind for women using hormone-replacement therapy to battle the symptoms of menopause.
University of Illinois researchers have found that being physically fit can slow the decline in cognitive brain functions associated with the long-term use (11 years or more) of hormone-replacement therapy. What's more, exercise can even improve the cognitive functions of women who use hormone-replacement therapy for less than 10 years.
For these shorter durations, "It may be that a combination of hormone-replacement therapy and exercise boost both cognition and brain structure of older women," says Arthur Kramer, U of I professor of psychology in the College of Liberal Arts and Sciences.
The study, which was led by Kramer and postdoctoral student Kirk Erickson, looked at how well 54 postmenopausal women performed on a computerized version of the Wisconsin Card Sort Test, which challenges memory, inhibition, and task-switching abilities.
Participants ranged in age from 58 to 80 with a mean age of 70. Aerobic fitness was measured by monitoring respiration, heart rate, and blood pressure during a treadmill test.
According to Kramer and Erickson, they took magnetic resonance images (MRI) of the participants' brains and segmented the images into 3-D maps. Then they used these maps to analyze the brain's gray matter, which is generally responsible for information processing, and the white matter, which is responsible for information transmission.
Kramer and Erickson found that long-term hormone use resulted in significantly less gray-matter tissue volume in four regions of the brain. However, the gray-matter volume reduction was not as great for women with higher fitness scores.
As for white matter, the interaction of hormone therapy and fitness had no significant effects in general. But higher fitness levels were tied to greater white matter in the prefrontal regions, as well as in a key area that interconnects frontal areas of the brain.
Women using hormone therapy for less than 10 years saw the increased brain tissue volumes, the researchers reported. But after 11 to 15 years of hormone-replacement therapy, the brain tissue volume began to decline.
Kramer stresses that these preliminary findings were based on only a small sample of women and need to be considered in a broader clinical setting. However, he says the findings mirror similar studies in his lab that continue to show the benefits of physical fitness in older people.
The research was funded by the National Institute of Aging and the Institute for the Study of Aging.
