Exercise boosts blood flow to the brain, study finds
The results add to growing evidence that exercise programs may help older adults slow the onset of memory loss and dementia

Date:
March 23, 2021
Source:
UT Southwestern Medical Center
Summary:
It's not just your legs and heart that get a workout when you walk
briskly; exercise affects your brain as well. A new study shows
that when older adults with mild memory loss followed an exercise
program for a year, the blood flow to their brains increased.



FULL STORY ==========================================================================
It's not just your legs and heart that get a workout when you walk
briskly; exercise affects your brain as well. A new study by researchers
at UT Southwestern shows that when older adults with mild memory loss
followed an exercise program for a year, the blood flow to their brains increased. The results were published online today in the Journal of Alzheimer's Disease.


========================================================================== "This is part of a growing body of evidence linking exercise with brain health," says study leader Rong Zhang, Ph.D., 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." As many as one-fifth of people age 65 and older have some level of mild cognitive impairment (MCI) -- slight changes to the brain that affect memory, decision-making, or reasoning skills. In many cases, MCI progresses to dementia, including Alzheimer's disease.

Scientists have previously shown that lower-than-usual levels of blood
flow to the brain, and stiffer blood vessels leading to the brain,
are associated with MCI and dementia. Studies have also suggested that
regular aerobic exercise may help improve cognition and memory in healthy
older adults. However, scientists have not established whether there is a direct link between exercise, stiffer blood vessels, and brain blood flow.

"There is still a lot we don't know about the effects of exercise on
cognitive decline later in life," says C. Munro Cullum, Ph.D., professor
of psychiatry at UTSW and 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." In the study, Zhang, Cullum, and their colleagues followed 70
men and women aged 55 to 80 who had been diagnosed with MCI. Participants underwent cognitive exams, fitness tests, and brain magnetic resonance
imaging (MRI) scans. Then they were randomly assigned to either follow
a moderate aerobic exercise program or a stretching program for one
year. The exercise program involved three to five exercise sessions a
week, each with 30-40 minutes of moderate exercise such as a brisk walk.



==========================================================================
In both programs, exercise physiologists supervised participants for the
first four to six weeks, then had the patients record their exercises
and wear a heart rate monitor during exercise.

Forty-eight study participants -- 29 in the stretching group and 19 in the aerobic exercise group -- completed the full year of training and returned
for follow-up tests. Among them, those who performed aerobic exercise
showed decreased stiffness of blood vessels in their neck and increased
overall blood flow to the brain. The more their oxygen consumption (one
marker of aerobic fitness) increased, the greater the changes to the
blood vessel stiffness and brain blood flow. Changes in these measurements
were not found among people who followed the stretching program.

While the study didn't find any significant changes in memory or other cognitive function, the researchers say that may be because of the
small size or short length of the trial. Changes to blood flow could
precede changes to cognition, they say. They're already carrying out a
larger two-year study, Risk Reduction for Alzheimer's Disease (rrAD),
that further investigates the link between exercise and cognitive decline.

"There are likely some people who benefit more from exercise than others,"
says Cullum. "But with the sample size in this study, it was hard to
analyze subgroups of people to make those conclusions." Still, the data
are important to help explain the effects of exercise on the brain and
why it can be beneficial, say Zhang and Cullum, who are members of the
Peter O'Donnell Jr. Brain Institute.

"Having physiological findings like this can also be useful for physicians
when they talk to their patients about the benefits of exercise,"
says Zhang. "We now know, based on a randomized, controlled trial, that exercise can increase blood flow to the brain, which is a good thing."
Cullum holds the Pam Blumenthal Distinguished Professorship in Clinical Psychology at UT Southwestern.

This research was supported with funds from the National Institutes of
Health (R01AG033106 and R01HL102457).

========================================================================== Story Source: Materials provided by UT_Southwestern_Medical_Center. Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. Tsubasa Tomoto, Jie Liu, Benjamin Y, Tseng, Evan P. Pasha,
Danilo Cardim,
Takashi Tarumi, Linda S. Hynan, C. Munro Cullum, Rong
Zhang. One-Year Aerobic Exercise Reduced Carotid Arterial Stiffness
and Increased Cerebral Blood Flow in Amnestic Mild Cognitive
Impairment. Journal of Alzheimer's Disease, 2021 [abstract] ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/03/210323131213.htm

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