Human Exposure to Iodine from the Consumption of Edible Seaweeds

The increasing consumption of wakame algae (Undaria pinnatifida) and kombu (Laminaria ochroleuca) because of their culinary appeal and beneficial properties means there is a need to study the composition of these new foods. Algae stand out for their high iodine content, this being an essential element whenever it is ingested at recommended levels but which, ingested in high quantities, can cause harmful effects to health such as hyperthyroidism and even goiter. The iodine content in 30 samples of algae from different geographical origins (Asia and Europe) has been determined by oxidation-reduction titration with sodium thiosulfate. European kombu algae (27.7 +/- 5.4 mg/kg dry weight) have the highest mean average iodine concentrations. European algae have higher iodine content than Asian algae. Significant differences (p < 0.05) have been recorded among wakame algae according to geographical origin. The consumption of 4 g/day of European kombu algae means an intake of 111 mu g/day of iodine, which is a value close to the RDI (recommended daily intake) set at 150 mu g/day. It is necessary to monitor iodine levels in algae to avoid excessive intakes and harmful effects on health.