Exercise, even brisk walking, carries benefits beyond weight loss and muscle maintenance. A recent study indicates that older adults with mild memory loss, who engaged in an exercise program for a year, increased blood flow to their brains.
As many as 20% of adults over the age of 65 have some level of mild cognitive impairment (MCI), slight brain changes that affect memory, decision-making or reasoning skills. In many cases, MCI progresses to dementia, including Alzheimer’s disease. A new study conducted by researchers at UT Southwestern Medical School (UTSW) in Dallas indicates that older adults with mild memory loss who followed an exercise program for a year experienced increased blood flow to their brains. Study results were published online in the Journal of Alzheimer’s Disease.
“This is part of a growing body of evidence linking exercise with brain health,” said study leader Rong Zhang, PhD, a professor of neurology at UTSW. “We’ve shown for the first time in a randomized trial in these older adults that exercise gets more blood flowing to your brain.” Scientists have previously found that lower-than-usual levels of blood flow to the brain, along with stiffer blood vessels leading to the brain, are associated with MCI and dementia. Additional studies have suggested that regular aerobic exercise may help to boost cognition and memory in healthy older adults.
“There is still a lot we don’t know about the effects of exercise on cognitive decline later in life,” said C. Munro Cullum, PhD, a professor of psychiatry at UTSW and co-senior study author. “MCI and dementia are likely to be influenced by a complex interplay of many factors, and we think that, at least for some people, exercise is one of those factors”
The study followed 70 men and women aged 55 to 80 who had been diagnosed with MCI. Researchers performed cognitive exams, fitness tests and brain magnetic resonance imaging (MRI). Then they randomly assigned groups to follow either a moderate aerobic exercise program (30 to 40 minutes of moderate exercise between three and five times per week) or a stretching program, both over a period of one year.
The researchers supervised participants for the first four to six weeks, after which the participants recorded their exercises and wore heart rate monitors during exercise. Among the 70 participants initially enrolled in the study, 48 completed the entire year of training and returned for follow-up tests. They included 29 in the stretching group and 19 in the aerobic exercise group.
Among those, participants who engaged in aerobic exercise exhibited decreased stiffness of blood vessels in their necks and increased overall blood flow to the brain. The greater their oxygen consumption increase, the greater the changes to the blood vessel stiffness and brain blood flow. Change in these measurements were not found in the group who followed the stretching program.
Although the study indicated no significant changes in memory or other cognitive function, the researchers suggested that may be due to the small size or short duration of the trial. Researchers noted that changes to blood flow could precede changes to cognition. “There are likely some people who benefit more from exercise than others, Cullum explained. The study data are important to help explain the effects of exercise on the brain. And, researchers noted, it’s important for older adults to recognize the benefits of exercise.
It’s never too late to adopt an exercise program. It’s advisable to speak with your provider to determine a safe and appropriate exercise routine to work into your daily schedule.