Foods: Functional Foods, Food Additives and Dietetic Supplements

Foods are composed of a variety of natural compounds with nutritional effects. However, some of them may also possess anti-nutritional and thyroid toxic effects, such as glucosinolate compounds, which are present in foods derived from higher plants. Currently, functional foods have been incorporated as sources of nutrients to our diet in order to meet certain nutritional requirements not present in conventional food; their effects on the thyroid gland are unknown and should be determined in order to perform a complete risk assessments of these foods. Food supplements, which are used widely by the population in many countries, are another source of nutrients, especially minerals and trace elements such as iodine and zinc that are necessary for the proper functioning of the thyroid gland, but if their use is not controlled they may induce alterations of the thyroid system. Furthermore, many of these dietary supplements also contain plants, algae and soybean in their composition that can exert harmful effects on normal thyroid function. Finally, during food processing different chemical compounds such as nitrate and erythrosine could be used, which could also induce harmful effects on the thyroid system. This chapter will discuss all of the foods and supplements mentioned above and their possible effects on normal thyroid function.

Keywords: Dietetic supplements, food, food additives, functional foods.