Trace elements and food safety

Abstract

Food is our energy source and limited access to food impacts health in multiple ways. Typically, food is thought to have a positive impact on health by providing energy and essential nutrients to living beings. Despite this, often it is so detrimental to health and several foodborne diseases clearly indicate that food safety not only involves availability and access to food, but that the food must be wholesome as well. The threat to food security is depending on urbanization, income disparity, overpopulation, ecosystem degradation, animal health, etc. Trace elements are essential components of biological structures, but at the same time they can be toxic at concentrations beyond those necessary for their biological functions. Variation in uptake in the gastrointestinal tract varies depending on chemical form, salt or ionic form, dietary matrices, and interactions with other nutrients. Adverse effects can occur from too low or too high intake of an essential element. Therefore, it may not be possible to arrive at recommendations that working for all individuals, since some persons with genetically determined metabolic disorders may require intakes that are higher or lower than those indicated by the acceptable range of daily oral intake. Important advances has been made in the last decades in our understanding of the environmental biochemistry, biological effects and risks associated with trace elements. This chapter provides a general picture on the essentiality of trace elements as a function of their role as catalytic or structural components of larger molecules, trying to focus the attention on the fine line between Essentiality and Toxicity. A general survey, because of the impossibility to draw a common guideline for all elements considered, is reported for each elements, that is on their geochemistry and biological functions in humans. In details, for each element an account is given of the mean total quantity accumulated by the human body, the distribution in the main organs, the most important pathways for their uptake and the recommended daily intake.