Empirical analyses of the influence of diet on human concentrations of persistent organic pollutants: A systematic review of all studies conducted in Spain

BackgroundNumerous studies analyzed concentrations of persistent organic pollutants (POPs) in human samples, and in many types of foods; however, food consumption is less commonly included in studies on the determinants of POP concentrations in humans, and these approaches are rarely integrated with surveys of food intake to estimate the amount and safety of human POP intake from food.ObjectiveTo analyze the main characteristics and findings of all studies conducted in Spain that quantitatively assessed the influence of diet on human concentrations of POPs.MethodsStudies published until December 2010 (with no other time restrictions) were identified through Medline/PubMed, ISI-Thomson, ScienceDirect, and SciELO databases.ResultsWe identified 25 papers, from 19 different studies. Twelve papers were published in 2009–2010. All studies but one were based on subgroups not representative of the general population, and over half were limited to women. Serum was the most used biological matrix, while p,p′-DDE, HCB and PCBs were the most frequently analyzed compounds. Food intakes were measured with heterogeneous food frequency questionnaires. The most consistent association was between fish consumption and PCBs and HCB, followed by dairy products and PCBs. A few studies observed a relationship between meat and some POPs, whilst intake of vegetables, fruits and cereals was rarely related to POP levels. Only 3 studies did not find any relationship between dietary habits and POP concentrations.ConclusionsIn spite of methodological heterogeneity, the studies were able to quantify to what extent consumption of foods from animal origin (fish, milk, dairy products and meat) is related to higher body concentrations of POPs. As in a few other countries, in Spain food consumption is increasingly analyzed as a major determinant of human POP intake.

Research highlights
► The most consistent association was between fish consumption and PCBs and HCB.
► It was followed by dairy products and PCB concentrations.
► Intake of vegetables, fruits and cereals was rarely related to human POP levels.
► Only 3 studies did not find a relationship between diet and POP concentrations.
► Food consumption is a major determinant of human POP intake.