Risk assessment of substances used in food supplements: the example of the botanical Gymnema sylvestre

Botanicals and preparations derived from these are among the substances frequently added to foods and food supplements, yet the safety of many botanicals has not been systematically assessed. In the context of the EU‐FORA fellowship programme, the fellow performed an assessment on the safety of the botanical Gymnema sylvestre, in accordance with EFSA's guidance on the assessment of safety of botanicals. Although preparations of G. sylvestre are marketed as food supplements, they may appeal to people who are suffering from metabolic syndrome and/or diabetes mellitus. A scientific literature search was carried out using PubMed/MEDLINE and EMBASE electronic databases. Experience was gained by the fellow in systematic data extraction from scientific publications, structuring of the data and evaluating toxicological key parameters, outcomes of clinical significance, pharmacokinetic and pharmacodynamic interactions, uncertainties and methodological shortcomings of studies. Limited evidence from toxicological in vivo studies and human clinical studies suggested lack of relevant adverse effects of this botanical. However, human studies provided some indications that certain Gymnema extracts may enhance the glucose‐lowering effects of certain antidiabetic drugs. Considering the uncertainties for the composition of different Gymnema preparations, potential herb–drug interactions and the indications of glucose lowering or hypoglycaemic effects, the use of Gymnema‐based food supplements in combination with authorised antidiabetic drugs may be associated with risks. The procedures learned for the safety evaluation of Gymnema may be similarly applied by the fellow for the risk assessment of other substances with nutritional or physiological effect added to foods and food supplements. Furthermore, apart from learning by conducting exercises in risk assessment, the fellow was able to develop other skills (e.g. communication skills), diversify his competencies and expand his network of scientific connections for future collaborations in the field of nutritional risk assessment.