Exercise for Blood Flow to the Brain and Better Aging

Researchers at UT Southwestern have reported their observations of older adults with mild memory loss who followed a physical exercise program for a year. The researchers found that blood flow to the brain increased.

"This is part of a growing body of evidence linking exercise with brain health," says study leader Rong Zhang. "We've shown for the first time in a randomized trial in these older adults that exercise gets more blood flowing to your brain."

Research shows that mild cognitive impairment (MCI) affects one-fifth of people age 65 and older. It manifests with mild issues in memory, decision-making, or reasoning skills.

The researchers followed 70 men and women aged 55 to 80 who had been diagnosed with MCI. The participants were randomly assigned to either follow a moderate aerobic exercise program or a stretching program for one year.

A study is published in Journal of Alzheimer's Disease. In it, the researchers report that the participants who performed aerobic exercise showed decreasing stiffness of blood vessels in their neck and increasing blood flow to the brain. Changes in these measurements were not found among the participants who followed the stretching program.

The length of the study was too short, according to the researchers, to reveal significant changes in memory or other cognitive functions. But the researchers are persuaded that changes to blood flow could precede changes that improve cognitive function. A larger ongoing two-year study, Risk Reduction for Alzheimer's Disease (rrAD), could confirm this.

Low levels of cerebral blood flow, and stiffer blood vessels leading to the brain, are known to be associated with MCI and dementia. Studies have also suggested that regular aerobic exercise may help improve memory and cognition in healthy older adults.

The new study is expected to confirm, clarify, and quantify the link between exercise, stiffer blood vessels, and brain blood flow. In the meantime, the completed study helps explain the effects of exercise on the brain. And it begins to help us understand how exercise may have beneficial effects on overall brain function and brain health.

"There is still a lot we don't know about the effects of exercise on cognitive decline later in life," says Munro Cullum, co-senior author of the study. "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. There are likely some people who benefit more from exercise than others."

"Having physiological findings like this can also be useful for physicians when they talk to their patients about the benefits of exercise," added Zhang. "We now know, based on a randomized, controlled trial, that exercise can increase blood flow to the brain, which is a good thing."

I don’t especially like exercise, and therefore I must keep persuading myself that exercise is good for me. I’m not (yet) experiencing MCI. But just in case, I’ll now stop writing this and go for a fast hike in the woods to improve blood flow to my brain.