A major review of the effectiveness of acupuncture has concluded that it is hard to find a difference between "true" and "sham" versions.
The research comes just a week after a similar review suggested that both could prevent headache. It looked at trials involving 3,000 patients with arthritis, migraine, low back pain and post-operative pain. The results questioned the "traditional foundation" of acupuncture, the British Medical Journal study concluded. The value of acupuncture remains highly controversial, with conflicting results from many studies.
Much of the argument surrounds the status of "sham" acupuncture, which is frequently used in trials against traditional acupuncture.
While traditional acupuncturists insert needles in acupuncture points located along what they describe as "energy meridians" - a concept for which many scientists say there is no evidence - sham acupuncture places needles away from these points.
However, the needles are still inserted beneath the skin in both varieties, and proponents of non-traditional acupuncture suggest that both varieties may be having a physiological effect - just not in the manner suggested by traditionalists.
The latest review, compiled by the Nordic Cochrane Centre in Copenhagen, found no "clinical relevance" to the differences between traditional and "sham" acupuncture, but found that patients given "sham" acupuncture did experience a small amount pain relief compared to those who had received no treatment.