April 20, 2021
A year-long aerobic exercise program that mostly involved brisk walking improved blood flow to the brain in older men and women at high risk of developing Alzheimer’s disease, according to a new report. The study adds to growing evidence that regular exercise may boost brain health and help to ward off Alzheimer’s disease and other forms of dementia.
For the study, researchers at UT Southwestern Medical Center enrolled 70 men and women with mild cognitive impairment, or MCI, a brain disorder marked by memory loss that half the time progresses to full-blown Alzheimer’s disease. The study participants ranged in age from 55 to 80, and they were randomly divided into two groups.
One group began a supervised aerobic exercise program over the next year. They began with three exercise sessions a week lasting 25 to 30 minutes, with a five-minute warm up and a five-minute cool down. They gradually built up to four or five exercise sessions each week lasting 30 to 40 minutes, including moderately intense exercises such as a brisk uphill walking that got the heart rate up to 85 to 90 percent of maximum.
The other group entered a stretching and toning class that included stretches of the arms and legs, as well as the use of elastic bands to provide resistance and toning. The exercise program did not involve aerobic activities that significantly elevate the heart rate.
Forty-eight of the study participants completed the full year of exercise training. Those who had done the aerobic workouts showed less stiffness of the blood vessels in the neck, as well as increased blood flow to the brain.
“We’ve shown for the first time in a randomized trial in these older adults that exercise gets more blood flowing to your brain, which is a good thing” said study leader Rong Zhang, a professor of neurology at UT Southwestern. Improved blood flow to the brain and decreased arterial stiffness have been linked in earlier research to a decreased risk of Alzheimer’s disease and other forms of dementia. The greater the improvements in aerobic fitness, the greater the improvements in blood flow to the brain, the study found.
Those who completed the stretching program did not show improvements in arterial stiffness or blood flow to the brain.
The study did not last long enough to prove that improved blood flow translated into improvements in memory and thinking skills. But the group is planning longer-term studies to assess whether aerobic exercise can improve scores on tests of memory.
“At present, there are not effective treatment strategies to prevent or slow age-related cognitive decline or Alzheimer’s disease,” the authors wrote. “These findings demonstrated the benefits of aerobic exercise training on reducing vascular risk factors in older adults who have high risks of Alzheimer’s disease.”
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Marc Flajolet, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: Tsubasa Tomoto, Jie Liu, Benjamin Y. Tseng, et al: “One-Year Aerobic Exercise Reduced Carotid Arterial Stiffness and Increased Cerebral Blood Flow in Amnestic Mild Cognitive Impairment.” Journal of Alzheimer’s Disease, April 2021. UT Southwestern Medical Center
