 |
 |
\Acupuncture activates the brain_files\spacer(1).gif)
Published online: 1
May 2005; | doi:10.1038/news050425-12
Acupuncture activates the brainAndreas von Bubnoff
Medicinal use of needles
does more than placebos.
Acupuncture has a measurable, if
mysterious, effect on the brain, UK scientists have found. The
study adds to evidence that patients benefit from acupuncture
not simply because of their expectations.
The
research team used brain imaging to show that treatment with
genuine needles activates brain areas beyond the ones that
light up when trick needles are used. "This is the first
brain-imaging study that has shown an effect beyond placebo,"
says George Lewith, an expert in complementary medicine at the
University of Southampton who led the study.
Acupuncture is an ancient Chinese treatment for
illness, pain or even addiction, which uses fine needles in
defined points of the body. The mechanism behind this is far
from understood, and clinical trials into acupuncture have had
mixed results. "It has worked in some trials, it hasn't worked
in others, it's very complicated," says Ted Kaptchuk, an
acupuncture researcher at Harvard University in Boston,
Massachusetts. Many studies have suggested that the placebo
effect accounts for most of the benefits seen.
 This is the first brain imaging
study that has shown an effect beyond
placebo.  |
George Lewith
University of
Southampton | | |
|
| Part of this confusion may be thanks to the use of
badly defined controls in acupuncture tests, experts say. Some
studies use needles in non-acupuncture points, for example.
But this may simply prove that needling is an effective
treatment.
Stage dagger
For a
better placebo, Lewith's team used a retractable needle that
doesn't really penetrate the skin, but tricks the patients
into thinking that it does. "It disappears into its handle
like a stage dagger," Lewith says. This tricked the patients
into believing they were being treated when they weren't.
The study group, which consisted of 14 patients with
arthritic pain in their thumbs, was also treated with both
real acupuncture, and with blunt needles that didn't penetrate
the skin. In the last case the patients were told that the
procedure should not have any effect.
The researchers then
used positron emission tomography to measure brain activity.
Both placebo treatment and real treatment activated the brain
in areas known to respond to opiates: painkillers released by
the brain.
Insula effect
True
acupuncture also increased activity in a different brain area
called the insula, which is part of the cerebral cortex. It's
not clear what this activity means, says Lewith, but it
indicates some sort of real effect. "What we have demonstrated
is that acupuncture is partially modulated by expectation, but
is probably also modulated by a real treatment effect," he
says. They report their findings in the journal
NeuroImage1.
Lewith adds that his own previous
work has indicated that expectation accounts for some of acupuncture's
benefits. In a study of people with chronic neck pain, they
found the placebo effect accounted for about 80% of pain relief2.
Kaptchuk says that the study should help researchers
to design better clinical trials of acupuncture in the future.
"This study gives a clarification of the possible mechanisms
by which acupuncture works, and by understanding the
mechanisms we can design better placebos," he says.
References
- Pariente J., White P., Frackowiak , Richard S. J.
& Lewith G. Neuroimage, 25. 1161
- 1167 (2005). | Article | PubMed |
- White P., Lewith G., Prescott P. & Conway J.
Ann. Intern. Med., 141. 911 - 919 (2004). | PubMed |
|
|
|
Story from
news@nature.com:
http://news.nature.com//news/2005/050425/050425-12.html | |
| |
\Acupuncture activates the brain_files\spacer(2).gif){kind=spacer}
