3 STROKECONNECTION Fall 2017
eing physically active may boost the brain’s fight
against the world’s No. 2 killer, according to new
About 795,000 Americans have a stroke
each year, and 129,000 die. But exercising
could lessen the severity of stroke later in life, according to
research that will be published in the Journal of Cerebral
Blood Flow and Metabolism.
Brain health depends on a network of blood vessels
called collaterals. The more you have, the better — because
collaterals carry blood to part of the heart when a coronary
artery is blocked, or to part of the brain when a cerebral
artery is blocked, providing protective benefits.
“You have collaterals in your heart, in your brain and in the
muscle and skin of your legs and arms,” said James Faber,
Ph.D., the study’s lead researcher and a professor in the
department of cell biology and physiology at the University of
North Carolina in Chapel Hill. “We’re quite interested in these
Since collaterals decline with aging, and strokes hit older
people the hardest — killing more brain tissue — researchers
set out to find out if exercise would prevent the loss of
collaterals and reduce the effects of stroke.
Faber and his colleague Wojciech Rzechorzek, M.D.,
looked at collaterals in two groups of mice. One group
was sedentary, while the other exercised
regularly on running wheels.
The sedentary mice, who were 80
human years when they had a stroke,
experienced large, severe strokes and
lost a lot of brain tissue or collaterals.
But the same-age running group fared
much better. Their collaterals stayed
steady and they had much less brain
damage after a stroke.
“Besides the many reported benefits of
regular physical activity, it is very possible
that regular, brisk walking, jogging or
running or any kind of aerobic exercise
has an additional effect of keeping blood
vessels young and abundant in the brain,
heart and lower legs,” Faber said.
Previous studies showed that collaterals
are very important in terms of prognosis
for stroke patients. These new findings might also apply to
people, meaning being physically fit could mitigate brain
damage after a stroke, but more research is needed.
“If you have a stroke but you have a lot of these
collaterals, that tissue will still get oxygen and nutrients.
If you have abundant collaterals, you could be eligible for
a thrombectomy [which removes blood clots], which will
benefit you,” he said. “But if you have poor collaterals, a
thrombectomy won’t have a benefit.”
Barry Franklin, Ph.D., director of preventive cardiology and
cardiac rehabilitation at William Beaumont Hospital in Royal
Oak, Michigan, said the findings are promising.
“Recent studies using advanced technologies have
suggested similar adaptations in the human heart as a result
of exercise training,” said Franklin, who was not involved in
the study. “These findings further reinforce the cardiovascular
and protective benefits of regular exercise. He added that
exercise pays off, even in spurts.
“Three 10-minute bouts equal the benefits of one
Regular exercise may
30-minute bout. I tell patients that when it comes to exercise,
you don’t have to put the dollar bill in the piggy bank at one
time,” Franklin said. “Four quarters, or even 10 dimes, will
provide the same payoff.”
Stroke can cause death or disability, including memory,
speech and vision loss; emotional problems and paralysis.
lessen stroke severity
By American Heart Association News