Estimation of cadmium load from soybeans and soy-based foods for vegetarians

Soybeans, as legumes, belong among food items that contribute most to the dietary intake of the heavy metal cadmium (Cd). The consumption of soy-based foods may contribute significantly to Cd intake in vegetarians as probably the most frequent consumers of these foods. In this research, the weekly dietary intake of Cd from soy-based foods was investigated in 119 participants (including vegetarians, vegans, and non-vegetarians) in the Czech Republic by means of a semi-quantitative food frequency questionnaire (SFFQ) with personal assistance and the measurement of body weight. Cd content in soy-based foods available on the market was determined by means of atomic absorption spectrometry after microwave digestion. Tofu, as the most frequently consumed food item in the vegetarian/vegan group, contributed most to the total dietary Cd intake. It contained 7.6 ± 0.1 μg Cd/kg, while the highest Cd content was observed in tempeh (18.1 ± 0.4 μg/kg). The highest mean dietary Cd intake per week from soy-based foods was 0.4 μg/kg b.w. and was found in the vegan group. The consumption of soy-based foods was the lowest in the non-vegetarian group as was the dietary intake of Cd, which was 0.04 μg/kg b.w. per week.