Background: This review aims to map the evidence on the effectiveness of Complementary and Alternative Medicine (CAM) for Type 2 Diabetes Mellitus (T2DM) and its associated complications and identify research gaps in key outcomes and CAMs.Methods: We followed the Johanna Briggs Institute guidelines to undertake this scoping review. We carried out a comprehensive search from inception to March 2020 in electronic databases and registers. Forward and backward citations of included studies were also searched. The randomized controlled trials (RCTs) and non-randomized studies with intervention and control arm were mapped based on the effectiveness of various CAM (Yoga, Ayurveda, Homeopathy, Siddha, Naturopathy, Unani, and Sowa-rigpa) on outcomes among individuals with prediabetes or metabolic syndrome, T2DM with and without any comorbidities.Results: A total of 249 studies were included after screening 3798 citations. Most of the included studies were conducted in India and Iran. Most frequently studied CAM interventions include Yoga, Ayurveda, and herbal products as compared to other CAM therapies.Conclusion: Although we identified a lot of literature on the effectiveness of CAMs for T2DM, there is a lack of standardization of preparation of these medicines and the interventional modalities. To validate the potential benefits of CAM, robust research with high-quality RCTs and systematic reviews are needed to bridge the gap of evidence in CAM therapies. Future investments for research in CAM may focus on assessing the quality of existing trials and finding out an optimal dose, frequency, and duration of CAM, both as an alternative and complementary approach.
