Hidden phosphorus: identification of phosphorus-based additives in processed foods according to the information provided in their nutritional labels

Abstract

Food additives containing phosphorus are increasingly being added to dietary products. Their addition to processed foods is due to various reasons: as preservatives, as leaving agents or as flavor enhancers. As these additives are being incorporated to dietary products that naturally contain phosphorus as well as those that do not contain it, the estimation of total phosphorus content by food tables or software programs becomes difficult, considering this addition as a hidden source of phosphate. Thus we decided to evaluate in a series of processed foods, grouping them by type of dietary product, if the label mentioned the presence of food additives containing phosphorus (as described by the Argentine Alimentary Code in its resolution MERCOSUR about additives). We analyzed the labels of 81 processed foods divided in 7 groups: 1) dairy products, 2) sausages and derivatives, 3) meat and derivatives, 4) bread and cookies, 5) cereals and derivatives, 6) drinks, and 7) others. We found additives containing phosphorus in 81 products, in 72 of the labels the specific additive or additives were mentioned; in 9 labels only the number of the additive was mentioned. There was no mention as how much phosphorus was present in the product in any of them. Of the 81 products with phosphorus additive, 31 were from the group of bread, cookies, snacks and sweets. This is a group of dietary products low in proteins and phosphorus that we generally do not indicate to be taken with phosphate binders. The great majority of these dietary products are part of the eating habits of children, adolescents and young adults. We conclude that until the moment we have the quantitative information about the real phosphorus content of the products available it is useful to assess the patients with poorly controlled hyperphosphatemia to consume fresh unprocessed foods and to have a list of the processed products with their label contents to better distribute the phosphate binders.