Assessing the safety of herbal medicine use among type 2 diabetes mellitus patients: A systematic review and meta-analysis

BACKGROUND: Herbal medicines (HM) use among type 2 diabetes mellitus (T2DM) patients has grown tremendously despite the existence of conventional treatments. However, evidence on their safety, potential side effects, and interactions remains scarce. This systematic review and meta-analysis aim to determine the global prevalence of HM use among T2DM patients and assess the safety and potential interactions. METHODS: A systematic search of four electronic databases was conducted until March 2024. Data were extracted and then assessed through an adapted quality appraisal tool. A meta-analysis estimated the pooled prevalence of HM use among T2DM patients and examined predictors of use. Identified herbs were classified based on safety and potential interactions with pharmacological treatments. The study followed PRISMA guidelines. RESULTS: Twenty-two cross-sectional studies from 19 countries were included. The global prevalence of HM use among T2DM patients was 53%, with significant regional variations. The highest prevalence of HM use among T2DM patients is in the African region, accounting for 39.8% of global HM use. Among 49 identified herbs, Opuntia ficus-indica L., Trigonella foenum graecum L., Allium sativum L., and Cinnamomum verum J. were the most commonly used. The safety classification reported 7 contraindicated herbs and 19 requiring caution, and 23 considered safe for use. Additionally, 12 herbs reported potential pharmacological interactions. CONCLUSIONS: Although the use of HM is widespread globally, multiple herbs pose safety concerns. Therefore, to preserve patients' safety, it is essential to avoid using contraindicated herbs and to seek healthcare practitioner supervision.