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Study after study has shown acupuncture to be effective in treating a host of different ailments, but new research is raising questions about why the ancient Chinese practice works.

Patients in the study suffering from frequent migraine headaches got better when treated with acupuncture. But acupuncture was found to be no more effective than so-called "sham" treatment, in which acupuncture needles were placed in areas of the body that are not believed to be active acupuncture points.

"The theory that acupuncture works because the needles are placed in very specific spots hasn't been proven to be the case in this study," researchers Klaus Linde, MD, tells WebMD. "It may make a difference for other conditions like osteoarthritis, but for migraines it doesn't seem to matter where the needles are placed."

In both groups the average number days per month with moderate to severe headaches declined from roughly five to three.

The new study is published in the May 4 issue of The Journal of the American Medical Association.

Ancient and Modern Theories

According to traditional Chinese belief, acupuncture targets a life force known as qi (pronounced "chee"), usually described as the normal functional energy associated with all living processes. It is thought that more than 200 specific acupuncture points exist along the pathway in which this energy must travel for good health. Imbalances in this vital life energy are said to result in disease.

The view of Western medicine is somewhat different. Modern science professes that acupuncture needles may stimulate nerves, altering messages from the brain and spinal cord. Acupuncture treatment is believed to promote the release of endorphins — the body's natural pain relievers — and other neurotransmitters like serotonin.

In the newly reported study, researchers from Munich, Germany's Center for Complementary Medicine Research randomly assigned 302 patients who suffered from frequent migraine headaches to receive either traditional acupuncture, "sham" acupuncture, or no acupuncture at all.

Both acupuncture groups underwent 12 sessions over eight weeks, and both groups reported the same decline in moderate or severe headache days in the month after the treatment ended. Roughly half of all patients who received acupuncture treatment reported at least a 50 percent reduction in headache days, compared with 15 percent of the nonacupuncture patients.

Treatment Not a Sham

The study is not the first to find "sham" acupuncture to be as effective as the real thing. While it is not clear why, Linde says there are probably both physical and psychological factors involved.

It has been suggested that hands-on therapies that involve repetitive stimuli like acupuncture and massage can alter the perception of pain.

The benefits may also be derived from the patient's belief that acupuncture works — the so-called "placebo effect" — and the ritual associated with treatment, Linde says.

Acupuncture expert Peter Wayne, PhD, says the impact of the hands-on interaction between the patient and the acupuncture provider can't be underestimated. Most acupuncture sessions take around 30 minutes, far longer than the average patient sees a doctor during a routine office visit.

Wayne is research director of the New England School of Acupuncture in Watertown, Mass.

"There are some very creative studies under way right now examining the effect of the interaction between patients and their practitioners," he tells WebMD. "In conventional medicine the time spent with a doctor is getting shorter and shorter, and we don't really understand the implications of this."

By Salynn Boyles, reviewed by Brunilda Nazario, MD

SOURCES: Linde, K.The Journal of the American Medical Association, May 4, 2005; vol 293: pp 2118-2125. Klaus Linde, MD, Center for Complementary Medicine Research, Technische University, Munich, Germany. Peter Wayne, PhD, director of research, New England School of Acupuncture, Watertown, Mass.