Acupuncture: an old debate continues - effectiveness of pain alleviation

Science News, August 20, 1988 by Rick Weiss

Acupuncture: An old debate continues

Controversy about acupuncture's usefulness as a painkiller continues to rage. In the past 10 years, a small but steady stream of research has suggested that certain acupuncture treatments are indeed analgesic. But the ongoing mystery of acupuncture's mechanism of action -- and the less-than-ideal experimental designs characteristic of so many acupuncture trials--have left many Western scientists and journal reviewers skeptical. From the range of findings reported last week:

* Joseph M. Helms, a physician with the American Academy of Acupuncture in Berkeley, Calif., performed acupuncture treatments on 43 women diagnosed with primary dysmenorrhea (menstrual pain). Some of the women received real acupuncture treatments, some received placebo acupuncture (shallow needle treatments, not at actual acupuncture points), some had monthly, nonacupuncture visits with the doctor and some were followed with no intervention.

The women recorded "monthly pain scores" based on intensity and duration of menstrual pain during a three-month treatment period and for nine months following the cessation of treatment. Later, researchers compared these levels to pretreatment scores, calculated by the women at the beginning of the study. These scores described pain levels for either the month previous to treatment or from an average of the preceding six months, whichever value was highest.

In the real acupuncture group, 10 of 11 women showed significant improvement (defined as pain scores averaging less than half the pretreatment scores). Four of 11 in the placebo acupuncture group showed improvement. Of the other two nonacupuncture groups, 2 of 11 and of 10 showed improvement.

In addition, Helms says, the real acupuncture group required 54 percent fewer pain medications during treatment and 41 percent fewer during the nine-month follow-up. No other group showed similar reductions.

* If acupuncture does alleviate pain, does it do so by activating the body's own opioid (painkilling) system in the brain? J. Ronald Lake and David H. Malin at the University of Houston-Clear Lake, Malcolm Skolnick at the University of Texas Health Sciences Center in Houston and their colleagues measured rats' responses to a standardized, mildly painful stimulus with and without acupuncture pretreatment, and with and without injection of the opioid-blocking drug, naloxone. By using flinch responses to small electrical currents as a measure of pain thresholds, they found significant pain reduction among rats pretreated with acupuncture. And in support of the opioid mechanism of action, they found that giving naloxone blocked the analgesic effects of acupuncture.

* Benson Martin of the University of Pennsylvania School of Veterinary Medicine in Kennett Square used laser-beam acupuncture for the treatment of chronic back pain in racehorses. Of the various means of stimulating acupuncture points in horses, Martin says, infrared laser stimulation has advantages over needles. "Horses don't like having needles stuck in them, but they don't the laser," he says. Martin used a 300-microwatt laser (enough to create a sense of "tingling" in human skin), treating nine acupuncture points on each horse, once a week for an average of 12 weeks.

Before treatment, Martin says, "all 15 of these horses were unable to perform at all at an acceptable level to the owner, trainer or veterinarian." After acupuncture, he says, performance was improved in 11 of 14 horses (one was sold and lost to follow-up), as measured by their ability to race with acceptable results. Four of the 11 went on to win races.

Martin concedes that such data provide no way to rule out natural healing of injuries. But he notes that despite numerous other treatments, the horses had remained disabled for as long as four years.