Korean researchers say they have unraveled the mystery behind the pain alleviation effects of acupuncture.

The Acupuncture and Meridian Science Research Center at Kyung Hee University announced the result of its research into the mystery Friday.

The team, jointly led by Professor Park Hee-jun and the University of North Carolina's Professor Park Jong-bae determined that pain relief is the result of biochemical skin reactions to the acupuncture needle.

The team said that after animal testing, it found that acupuncture notably activated the signal transfer in the surface and inner skins, and that the increased signal activities play an important role in recognition of pain in the central nervous system.

The findings are published as the cover story in the May issue of Journal of Pain.