Bioavailability and exposure to cadmium from chocolate consumption: a nutritional study

Since 2019, new European limits apply to cadmium (Cd) in cacao-derived products. These limits largely affect the South American cacao industry, where Cd concentrations in cacao beans are naturally large. The basis of the regulation is a risk assessment showing that children regularly eating chocolate exceed the tolerable Cd intake, assuming that Cd in chocolate is equally bioavailable as in other food items. This study aims to test that assumption by measuring in vivo Cd bioavailability in chocolate products relative to other food items. In so doing, this study will identify if regular chocolate consumption increases the Cd exposure and systemic uptake in humans. First, Cd dietary exposure of the general Belgian population will be estimated, with special attention to high chocolate consumers. Second, dietary Cd uptake and intake will be compared between a test group (regularly eating dark chocolate with high Cd) and a control group (low chocolate consumption). Cadmium in duplicate diets and blood Cd will be measured, from which the relative Cd bioavailability will be estimated. Finally, a dual-stable Cd isotope tracer ratio method will be developed to measure the gastrointestinal absorption of Cd from test meals with or without dark chocolate. This research can affect the Cd risk assessment and risk perception in the chocolate market. The study will be performed in collaboration with a partner (UGent) for isotope analysis and a partner (KU Leuven) working on dietary studies.