Background: Momordica charantia is not only a nutritious vegetable, but is also used in traditional medical practices to treat type 2 diabetes mellitus. Experimental studies with animals and humans suggested that the vegetable has a possible role in glycaemic control.
Objectives: To assess the effects of mormodica charantia for type 2 diabetes mellitus.
Search strategy: Several electronic databases were searched, among these The Cochrane Library (issue 4, 2009), MEDLINE, EMBASE, CINAHL, SIGLE and LILACS (all up to November 2009), combined with handsearches. No language restriction was used.
Selection criteria: Randomized controlled trials that compared momordica charantia with a placebo or a control intervention with or without pharmacological or non-pharmacological interventions were included.
Data collection and analysis: Two authors independently extracted the data. Risk of bias of trials was evaluated using the parameters of randomization, allocation concealment, blinding, completeness of outcome data, selective reporting and other potential sources of bias. A meta-analysis was not performed given the quality of data and the variability of preparations of momordica charantia used in interventions (no similar preparation was tested twice).
Main results: Three randomised controlled trials with up to three months duration and investigating 350 participants met the inclusion criteria. Risk of bias of these trials (only one study was published as a full peer-reviewed publication) was generally high. Two RCTs compared the effect of preparations from different parts of the momordica charantia plants and placebo on the glycemic control in type 2 diabetes mellitus. There was no statistically significant difference compared to placebo. The effects of preparation from the leaves of the plant and glibenclamide were comparable in the third trial. No serious adverse effects were reported in all the trials. There were no documentations of death from any cause, morbidity, (health-related) quality of life and costs.
Authors' conclusions: There is insufficient evidence to recommend momordica charantia for type 2 diabetes mellitus. Further studies are therefore required to address the issues of standardization and the quality control of preparations. For medical nutritional therapy, further observational trials evaluating the effects of momordica charantia are needed before RCTs are established to guide any recommendations in clinical practice.