9 out of 10 bloggers agree that 10 out of 100 scientists have interesting things to say about research 6 of one and a half dozen of the other times that you ask for information. If you can parse that sentence, then you may also enjoy Bausell's book Snake Oil Science which is jammed chock-a-block with detailed analyses and statistical reviews of research studies concerning alternative medicine, and he writes a fair bit better than my leading sentence would indicate. Bausell is well positioned to address the question; as a research methodologist, he has to go into bed with statistics on a regular basis, and keep from falling asleep.
His dissection of the science is careful, exacting, and step by step eviscerates some of the most beloved of alternative therapies leaving proponents of these therapies no basis for their confidence in the treatment other than faith. He does also prove, again with a direct approach and clear evidence, that placebo effects are strong and very real. His position in the book is to compare the CAM therapies with the placebos, to see if the therapies are better than the placebo. In only one case can he find a measurably better effect of the CAM over the placebo - green tea. And in that case, the effect is only that it lowers cholesterol, not that it is the panacea that some claim. Note also that Bausell does point out that even this study may be suspect, as it was paid for by industry funding.
I read the book hoping to find some substantiation of some treatments I'd been considering for persistent back pain I've had - having tried chiropractors, ultrasound therapy, physical therapy without relief, and I'm open to other options. And I did find that there is something out there that is non-toxic and economical - placebos. Now I just have to figure out a way to trick myself into believing. I did learn a lot more about the strength of the placebo effect, and how profoundly it can influence an improperly constructed study.
For further information on placebos, check out this presentation from Dan Ariely, author of Predictably Irrational.