"The meridians of acupuncture are no more real than the meridians of geography. If someone were to get a spade and tried to dig up the Greenwich meridian, he might end up in a lunatic asylum. Perhaps the same fate should await those doctors who believe in [acupuncture] meridians."
Yet there are meta-analyzes and even a lancet publication showing that acupuncture does have a modest significant effect over sham needles (but is not superior to standard treatment). This raises questions has to why an effect was observed. One possibility is bias, since the trials are not double-blind, the acupuncture practitioner knows when he is putting the needles in the supposedly real points or when he only inserts them superficially on random places. As such the patient may be consciously or subconsciously influenced to agree with the practitioner's own beliefs, even if he/she is well intentioned. Another possibility is that there is indeed a real effect. For example, inserting the needles in deeper may have elicited more pain signal and allowed the release of more endorphins than the superficial sham needles. I think the only way to truly test if acupuncture works would be to compare the same needles, inserted the same way in a double blinded manner. Someone who was trained on how to insert the needles but not "where" would be given two "maps" and not told which is which. Of course if that would fail to work the alternative medicine practitioners would probably say that it is an unfair comparison and that only they have the holistic energy channeling knowledge. But it would sure satisfy me.
Placebo is most potent in terms of reducing pain, which suffers a large influence from the state of mind. Another hallmark of placebo is that it tends to be most effective acutely and tends to diminish with time, and with repeated treatment. acupuncture seems to satisfy both these conditions.
Anyways all this was to introduce the Traditional Chinese Medicine Act, 2006, which allows tradional chinese healers to be called Doctors and allows them to communicate a diagnosis to a patient based on traditional practices in Ontario. I really do wish western evidence-based medicine and alternative medicine would be treated equally, that is that both would have to prove efficacy and safety in controlled trials. Soon we'll be in the same situation than the UK which has multi-million dollar homeopathetic state-funded hospitals, complete with ambulances.