A study by the Human Nutrition Unit of the Rovira y Virgilio University (URV) and the Pere Virgilio Health Research Institute (IISPV) has found a relationship between exposure to persistent organic pollutants through diet -especially dioxins- furans-, and the increase in body mass and adiposity, that is, the accumulation of fat.

After analyzing the diet and body composition of 5,899 adults aged 55 to 75 years, the researchers found that study participants with higher dietary intakes of dioxins and furans had higher body mass index and waist circumference than the rest. These people were also more likely to gain weight: they had a higher risk of increasing their waist circumference after one year of follow-up.

The research has also revealed that 87% of the population studied (a very large sample of volunteers participating in the Predimed-Plus study) exceeds the tolerable levels of these toxic persistent pollutants set by the European Food Safety Authority ( EFSA).

This is the first study to explore the association between dietary intake of dibenzo-p-dioxins or polychlorinated furans and the accumulation of fat in the body. Polychlorinated dibenzo-p-dioxins and furans are among the most toxic persistent pollutants released into the atmosphere because they are deposited on soil and vegetation, are highly insoluble in water, and break down very slowly, so they can accumulate in organisms (it accumulates mainly in animal fat) and enter the food chain.

In this sense, experts say that dioxins can accumulate and last in the human body for almost a decade and 90% of them come from what we eat. The products that contribute the most to its intake are red meat, fish and shellfish, because these types of substances accumulate in the fat.

“Those of us who study obesity see that there is a part of the problem that escapes interventions through diet and physical exercise, that there is something that resists us, and we think this study suggests that the answer may lie in environmental factors. , in exposure to contaminants”, explained to La Vanguardia Jordi Salas-Salvadó, professor of Nutrition and Bromatology at the URV and member of the Pere Virgilio Health Research Institute (IISPV) and CIBEROBN of the Carlos III Institute.

María Ángeles Martínez, principal investigator of the study, explains that the association between exposure to dioxins and furans and the increased risk of obesity that they have found in their work is consistent with the results of tests and other studies carried out on animals that have found evidence of that these contaminants are hormone disruptors that affect body composition, alter insulin resistance, and cause developmental problems.

It happens with persistent organic pollutants such as those studied in this URV research but also with other non-persistent ones but to which we are chronically exposed, such as bisphenol A. And this is causing the European authorities to progressively restrict the levels that allows the industry to use, “but they still do not prohibit them,” emphasizes Martínez.

Because, explains the expert, these chemicals continue to pose a serious health risk “and once they are released into the environment and accumulated in food, they cannot be eliminated, so the only way to reduce human exposure to them is from their source.” origin, that is to say, with rigorous controls of the industrial processes to minimize the formation of these toxic compounds”.

However, since the main exposure factor in the case of dioxins and furans is food, Salas-Salvadó and Martínez advise eating a balanced diet but reducing products of animal origin, especially red meat and fish, because it is there, in animal fat, where they accumulate the most.

In this sense, Salas-Salvadó points out that the fact that the participants in the PrediMed-Plus study have a high adherence to the Mediterranean diet and have a very internalized consumption of meat and fish could explain why practically nine out of ten of the people analyzed in this research exceed tolerable dietary levels of these contaminants.