REVIEW Focus on Alternative and Complementary Therapies Volume 17(3) September 2012 142–148 © 2012 The Authors FACT © 2012 Royal Pharmaceutical Society DOI 10.1111/j.2042-7166.2012.01159.x ISSN 1465-3753 Complementary and alternative medicine for diabetes mellitus: an overview of systematic reviews Paul Posadzki, Myeong Soo Lee, Edzard Ernst Abstract Background Many patients with diabetes mellitus report the use of CAM. Objectives To summarise and critically evaluate systematic reviews of any type of CAM for the treatment of diabetes. Methods Four electronic databases were searched to identify all relevant systematic reviews published between January 2000 and May 2011. Results Twelve systematic reviews met the inclusion criteria. These reviews evaluated the effectiveness of any type of CAM, herbal medicine, qi gong, tai chi, massage, moxibustion and yoga for the treatment and/or management of diabetes mellitus. Reviews also assessed the effectiveness of: pharmacological and lifestyle interventions to prevent or delay the onset of the disease; the effectiveness of herbal remedies and dietary supplements for glucose control; and the effectiveness of yoga-based programmes on physiologic and anthropometrical risk profiles and related clinical outcomes. Six reviews were of high quality and six indicated high risk of bias. Eleven reviews arrived at cautious or negative conclusions. One systematic review of massage reported positive conclusions. Conclusions Evidence supporting the effectiveness of CAM as a treatment option for diabetes is scarce. Keywords Complementary and alternative medicine • diabetes mellitus • effectiveness • systematic review Introduction Complementary and alternative medicine (CAM) has become increasingly popular among patients with diabetes mellitus (DM). Prevalence rates of CAM use among people with DM range between 17% and 73%; 1 the lifetime prevalence of CAM use in British patients with DM is 24%. 2 There might be several explanations for this high level of popularity; one reason is that CAM is being promoted as an effective treatment for DM and associated complications. Some patients with DM might also feel that their needs are not being met by mainstream medicine and, as a result, seek alternative treatments. 3 What- ever the reasons for CAM’s popularity are, it is impor- tant to know which forms of CAM are safe and effective for the treatment of DM. 4 Numerous trials of CAM for DM have been pub- lished, and several forms of CAM have been evalu- ated in systematic reviews (SRs). The aim of this article is to review and critically evaluate the data from systematic reviews of CAM for DM published within the past decade. Methods The literature was searched for systematic reviews of complementary and alternative medicine for DM published between January 2000 and May 2011. For the purpose of this review, CAM was defined as: 142