It doesn't matter whether acupuncture needles puncture the skin or not; the results on pain relief are about the same, Japanese researchers report in the online journal, Open Medicine.
Acupuncture is popular in alternative medicine as a treatment of pain, but its effectiveness has remained controversial.
Part of the problem has been designing a study that would allow it to be "double-blind" -- that is, one that allowed both the patients and the acupuncturists to be unaware of which patients were receiving real acupuncture and those receiving simulated.
Nobuari Takakura and Hiroyoshi Yajima of Tokyo Ariake University of Medical and Health Sciences solved that problem by developing non-penetrating placebo needles that appear like the real thing but that don't puncture the skin.
The researchers recruited 56 healthy volunteers to participate in the study: 35 men, 21 women. They provoked pain in the subjects' forearms using electrical stimulation. They then asked subjects to rate pain relief brought by various experimental conditions: penetrating needles, non-penetrating needles (placebo) and no acupuncture.
They found there was no significant difference in the pain-relieving effects between penetrating and non-penetrating needles.
"A significant analgesic effect was observed during needle application and immediately after needle removal for both the penetrating and non-penetrating needle trials when compared with the no-acupuncture control condition," they write.
The researchers also concluded that their needles can be used successfully for double-blind methodology for further acupuncture research, and they called for larger studies and studies on other types of pain.
Takakura owns international patents on the needles used for the study.
