A new and very large study now suggests that — even though no one really knows why — acupuncture might actually be effective.

The uncertainty of science: A new and very large study now suggests that — even though no one really knows why — acupuncture might actually be effective.

The key mystery here is the lack of any explanation for why acupuncture seems to work. And without that explanation, a large number of doctors will justifiable still refuse to use it as a course of treatment.