Caffeine can inhibit the analgesic effect of acupuncture, according to animal studies carried out in Brazil. Mice subjected to plantar incision surgery were treated with both manual acupuncture and electro-acupuncture at the acupoint Sanyinjiao SP-6 after administration of acute or chronic doses of caffeine. Researchers found that acute pre-administration of caffeine completely reversed acupuncture-induced analgesia (AA) for both types of acupuncture. The investigators also used doses that mimicked the average daily caffeine consumption in both Western countries and China. The Western dose of caffeine (70mg/kg/day) administered for eight days in drinking water reversed AA, while the Chinese dose (4mg/kg/day) administered for the same period did not. The authors suggest that caffeine intake levels could be a confounding factor in the context of human acupuncture research. (Caffeine at Moderate Doses Can Inhibit Acupuncture-Induced Analgesia in a Mouse Model of Postoperative Pain. J Caffeine Res. 2013 Sep;3(3):143-148).