Secret: Blood Flow to Brain
Acupuncture on pain-relief points cuts blood
flow to key areas of the brain within seconds, providing the clearest
explanation to date for how the ancient technique might relieve
pain and treat addictions, a Harvard scientist reports today.
Although researchers still don't fully understand
how acupuncture works, "our findings may connect the dots, showing
how a common pathway in the brain could make acupuncture helpful
for a variety of conditions," says radiologist Bruce Rosen of
Harvard Medical School. He'll release the findings at the American
Psychosomatic Society meeting in Orlando.
Rosen's team used functional Magnetic Resonance
Imaging, or MRIs, on about 20 healthy volunteers before, during
and after acupuncture. This type of brain scan shows changes in
blood flow and the amount of oxygen in blood.
Researchers applied acupuncture needles to
points on the hand linked to pain relief in traditional Chinese
medicine. Blood flow decreased in certain areas of the brain within
seconds of volunteers reporting a heaviness in their hands, a
sign the acupuncture is working correctly, Rosen says. The needle
technique is not supposed to hurt if done correctly. When a few
subjects reported pain, their scans showed an increase of blood
to the same brain areas.
"When there's less blood, the brain isn't
working as hard, " Rosen says. "In effect, acupuncture is quieting
down key regions of the brain."
The specific brain areas affected are involved
in mood, pain and cravings, Rosen says. This could help explain
why some studies have found acupuncture helpful in treating depression,
eating problems, addictions and pain.
The brain regions involved also are loaded
with dopamine, a "reward" chemical that surges in reaction to
everything from cocaine to food, beautiful faces and money. The
reduced blood flow could lead to dopamine changes that trigger
a "cascade" effect, releasing endorphins, the brain's natural
pain-relieving and comforting chemicals, Rosen says.
Rosen's study "is a very exciting first step,"
says neurobiologist Richard Hammerschlag of the Oregon College
of Oriental Medicine in Portland, but controlled research on pain
and addiction patients will be needed to prove the point. Brain
scans should be done on patients getting acupuncture at real and
bogus points, he says, and patients shouldn't know which group
The placebo effect is so powerful it could
affect blood flow, says UCLA neurobiologist Christopher Evans,
a pain expert. There's even some evidence that placebos can increase
brain chemicals, such as endorphins, Hammerschlag says.
Reference Source 117