Several members of my family have tried acupuncture and had great results. My mom quit smoking; my stepfather’s bad back improved. You’ve probably heard similar stories from friends or family. You might even have had success with acupuncture yourself.
Yet the science behind acupuncture is dubious. It’s difficult to properly control an acupuncture study because its practitioners—and those receiving treatment—are heavily invested in the results. In a Norwegian study of acupuncture as treatment for hot flashes during menopause, 80 out of 535 volunteers dropped out because they were randomly assigned to the “no treatment” group. As Euan Lawson, a general practitioner in Cumbria, UK, explained in his analysis of the research, acupuncture is quite popular in Norway, with nearly a third of the population having received the treatment at some point in their lifetimes. With this level of popular acceptance of acupuncture, it’s no wonder that a small apparent benefit was found: The women who received acupuncture reported experiencing slightly fewer hot flashes than those who remained in the randomly assigned “self-treatment” group. This result is easily explained as a placebo effect: The women and their practitioners both want the treatment to work and believe it will, so therefore it does, albeit only very slightly.
A better way to do acupuncture research is to use a sham acupuncture control group that leads both patients and practitioners to believe they are getting real acupuncture. Accordingly, researchers have designed “needles” that appear even to practitioners to be real but don’t puncture the skin. This is the same way careful drug trials are done: Patients and physicians don’t know whether they receive the experimental drug, an alternative drug, or a placebo.
David Gorski is a breast cancer surgeon at the Barbara Ann Karmanos Cancer Institute, an NIH-funded medical researcher, and an avid blogger with a passion for shredding medical myths. Over the years, as research into the efficacy of acupuncture has been more rigorously controlled, he says, positive results have evaporated. No study with a well-designed sham acupuncture control group has shown any advantage for real acupuncture. When there are any benefits compared to no treatment, both sham acupuncture and real acupuncture provide them, demonstrating that both are placebos.
But last June, a study using sham and real acupuncture claimed to find a benefit of real acupuncture: It activated receptors in the brain that are associated with reduced pain in patients receiving medication for fibromyalgia. A University of Michigan team led by Richard E. Harris gave 20 female patients PET scans to measure brain activity before and after treatment. The women who received real acupuncture showed more activity in the key area of the brain known to aid responsiveness to pain medication. Yet, as Gorski points out in his post discussing the study, there was no difference in pain experienced between the two groups. So although brain activity was changed by acupuncture, the main concern of the patients—relief of pain—was not.
Why was brain activity different? It’s hard to say what the mechanism for the difference was, but the key difference between these groups is that the real acupuncture group actually had needles puncturing their skin, while the sham group did not. Gorski suggests that this real physical difference between the groups may be all that’s necessary to cause the divergent brain activity.
So, one might ask, if this research has so many limitations, how does it get published at all? Doesn’t it get subjected to peer review? The answer, of course, is that it does, but peer review isn’t perfect. One report this year suggested that many of the greatest scientific discoveries in history wouldn’t have made it through peer review (though Anne-Marie Deitering’s blog post about the article disputes that notion). Another demonstrates that reviewers themselves are biased.
It may be better to consider peer review a baseline: Peer-reviewed work is usually serious science, worthy at least of more discussion and investigation. But a single peer-reviewed work doesn’t confirm a finding as permanent scientific truth—it’s a starting point for an ever-evolving conversation.
And in the case of the acupuncture research, what seems to be most important to reviewers is continuing the discussion of what’s still a commonly accepted practice, regardless of how difficult to design the experiments are.
By the way, not every member of my family was helped by acupuncture. My stepbrother tried it for his debilitating back problems and got no relief. Now, after surgery and physical therapy, he is slowly improving. Placebos can’t always substitute for real, science-based medicine.
Originally published September 2, 2009