Acupuncture Works--Sort of
Acupuncture: Physiology, Psychology, or Placebo?
Posted Sep 27, 2010
Acupuncture is becoming more widely accepted by doctors and health insurance companies for treating patients who find standard treatments inadequate, but in contrast to prescription drugs and medical procedures that must be proven safe and effective, there remains a mystique about acupuncture. How well does it work? Is acupuncture supported by sound physiological mechanisms or are the perceived benefits psychological?
Brian Berman and colleagues of the University of Maryland School of Medicine reviewed the scientific studies on acupuncture for treating chronic lower back pain, and published their findings in the July issue of the New England Journal of Medicine. Both believers and non-believers in the ancient pin-pricking procedure from the Far East will find support for their viewpoint in this study.
Most people (70%) have experienced serious lower back pain; indeed, lower back pain is one of the most common reasons for visits to a physician. Low-back pain can be disabling, but usually the pain responds to treatment. Unfortunately some people (7%) develop chronic low back pain that cannot be resolved with drugs or physical therapy. Many of these people turn to alternative therapies, including acupuncture, for relief.
Acupuncture originated in ancient China and today there are many different schools of acupuncture. All are based on the idea of restoring "harmony" in the body's flow of a mysterious energy force called "qi". The ancients describe 12 primary and 8 secondary invisible lines on the body (called meridians) where the energy force is believed to flow. Acupuncturists target these meridians at specific points to relieve various pains or cure other illnesses. The meridians correspond to nothing in the internal anatomy of the body, and the mysterious energy said to surge through the invisible channels is unknown to science.
In traditional acupuncture, the sticking of pins in people is accompanied by various other manipulations, which vary widely among different practitioners. Sometimes this includes examination of the tongue, recommendation of herbal medications, and taking the strength of one's pulse. The needles are inserted anywhere from ¼ inch to 1.5 inches deep. The number of needles used and exactly where on the meridians the therapist stabs them also varies among practitioners. Sometimes the needles are manipulated by the acupuncturist after they are inserted to increase stimulation, or the needles can be stimulated with mild electric current, heated, or herbs on the end of the needle set on fire.
A study of 6359 patients suffering chronic lower back pain compared the results of providing these patients with acupuncture, no treatment, or treating them with mock acupuncture. In mock acupuncture, the therapist went about the usual ritual as if to apply acupuncture, but then barely pricked the skin and targeted the pins more-or-less randomly, without regard to the mysterious meridians. The results showed that both the patients receiving real acupuncture and the ones receiving mock acupuncture experienced significant pain relief compared to people who received no treatment. Either acupuncture is so powerful it is not necessary to be very good at it --missing the bull's-eyes on the mysterious meridians and barely pricking the skin are sufficient--or the whole business is a mind-game placebo effect.
Still, doing anything might be better than doing nothing to relieve a person's pain, so in another study, patients were treated with acupuncture or mock acupuncture and compared with a third randomly assigned group of patients who were treated with the conventional low-back pain treatment of western medicine consisting of drugs, physical therapy, and exercise. The study found that both patients treated with real and mock acupuncture received significantly more pain relief than those treated with conventional medicine. A more recent study of 3093 patients found that when chronic low-back pain sufferers were treated with conventional medicine they did significantly better when they were also given acupuncture compared with those who received only conventional treatments.
The belief that a treatment will work can have a powerful effect on the outcome-especially an outcome involving the mind. It is difficult to study the physiological mechanisms of acupuncture, because the placebo effect is strong and the pain relief it provides is real. Measuring the body's physiological response to stabbing needles in it is certain to evoke physiological responses in the nerves and brain, but linking the body's physiological response to the psychological perception of reduced pain is difficult. Studies of pain and acupuncture in animals are of limited use. Ultimately, pain is in the mind, and the mind of humans differs enormously from that of any other animal, and so too must our sense of pain.
The outcome of this study raises larger issues. The human mind, with psychological features and capacities unmatched by animal brains, is not easily studied in laboratory animals. This quandary encompasses not only scientific investigation of treatments for pain but such vaguely understood practices as psychotherapy. Psychotherapy has many different schools of practice, and each one provides bona fide measures of success, but all rest on somewhat rocky biological foundations.
Berman, B.M. et al, (2010) Acupuncture for chronic low back pain. N. Engl. J. Med 363: 454-461
Fields, R.D. November 1, 2009 post New hypothesis for acupuncture. http://rdouglasfields.wordpress.com
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