A recent study by the prominent French consumer organization UFC-Que Choisir shows how cadmium in cocoa products directly threatens public health through ordinary dietary habits. Tests on chocolate bars revealed cadmium concentrations between 0.022 and 0.458 milligram/kilogram. While such levels reflect naturally occurring contamination in soils, their presence in a widely consumed product has serious implications.
The French and European food safety agencies (Anses and EFSA) have identified a maximum tolerable intake of about 0.35 micrograms per kilogram of body weight per day. This reference value is not a legal threshold but a health-based limit indicating the level beyond which risks rise. For a child weighing 30 kilograms, the tolerable dose is 10.5 micrograms daily; for an adult of 75 kilograms, 26.25 micrograms. Yet a single 20 g portion of chocolate can contain up to 9 micrograms of cadmium. This represents 85 percent of a child’s daily tolerable intake, and one-third for an adult. Consumption of an entire 100 g bar would surpass the maximum tolerable dose several times over for both adults and children.
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The health risks of cadmium are not hypothetical. Historical cases such as Japan’s “itai-itai” disease, caused by cadmium contamination of rice fields, highlight the severe health impacts of long-term exposure. Today, cadmium is recognized by the International Agency for Research on Cancer as a definitive carcinogen, while also being suspected of reproductive toxicity and endocrine disruption.
In the contamination of cocoa and the products derived from it, geology plays a clear role. Cocoa grown in regions of Latin America, like Colombia, Ecuador and Peru, where soils naturally contain higher cadmium concentrations, consistently shows elevated results. Simultaneously, these same regions supply much of the organic and fair-trade cocoa on the European market. Besides natural soil conditions, farming and industry practices further influence uptake: soil acidity, the recycling of plant material, and fertilizer use all contribute to the transfer of cadmium from soil to crop not only incocoa production but basic food groups like cereals and potatoes. Phosphate-based fertilizers are also a particularly important pathway, as they are also used in cocoa production and can further increase the cadmium contamination content of soils and then crop. Phosphate rock used in their production naturally contains cadmium, and repeated application over time increases soil contamination, especially in acidic soils. While phosphate-based fertilizers can contribute to cadmium accumulation in soils, they remain essential to modern agriculture. The use of low-cadmium phosphate fertilizers, combined with conscious soil and crop management practices, can help maintain productivity while reducing cadmium contamination risks.
Chocolate may have triggered renewed attention, but the underlying issue lies in how cadmium enters the food chain and how to mitigate natural and artificial cadmium contamination alike. Effective policy will require shifting the debate from the supermarket shelf to the agricultural field.
More information available at:
Cadmium contamination in food - Link
Summary of Regulation (EU) 2023/915 on maximum levels for certain contaminants in food – Link
Elsa Casalegno, Cadmium dans le chocolat. Une contamination bien réelle - Link
López-Zuleta, S., Cifuentes, E. E. A., Quiroga-Mateus, R., Toloza-Moreno, D. L., Rodríguez-Giraldo, Y., Huertas-Beltrán, R., & Bravo, D. (2025). Cadmium in fertilisers used for cacao production: a case study in Colombia. Food Additives & Contaminants: Part A, 42(9), 1213–1228 - Link