Acupuncture might help prevent migraines

"Might" it now? gimme a vicodin any day.

Among the study’s limitations, about 20 percent of the participants had previous experience with acupuncture, and it’s not known how many may have been able to guess whether their treatments were real or sham.

That's a pretty important limitation!

"For the sham treatment, the needles were placed in areas not known to be acupuncture points and the deqi sensation wasn’t induced."

So, the participants on the "true" acupunture group had a very obvious feeling of stimulation and the control group did not? well that is a clear example of a bad control. The only thing they had to take care was to eliminate every hint of the subjects about what group they were and this glaring difference is more than enough.

In acupuncture studies its always the same, as long as any of the groups have something extra to produce a placebo effect then some small change is being perceived, but on those studies where the control group is properly masked the difference disappear.

The important part of the comments of Dr Gelfand is that neither a researcher nor a clinician should support acupuncture. A researcher because the effects shown are always related to sloppy science (indicating no real effect), and a clinician because acupuncture is not free of risks therefore anything that would produce the same placebo effect but without those risks should be preferred (in this case sham acupuncture).