Published: 17.09.09
Phthalates in food

Eating sensibly doesn't protect you from harmful substances

Phthalates – the softening agents in synthetic materials – were a hot topic during the last decade and have been linked to deformities in the male genitals, diabetes, premature births and excess weight. Now, a study from ETH Zurich has revealed that they are extremely difficult to avoid, even if you eat healthily.

Simone Ulmer

Synthetic materials are omnipresent in our everyday lives. To make them soft, flexible, durable and nicer, PVC or synthetically produced rubber is mixed with an organic compound made up of phthalate ester and alcohol (otherwise known as phthalates), for example. The synthetics industry uses about five million tons of these softeners annually; they are present in conventional flooring, cables and packaging materials, but also medical products and cosmetics.

Easy pickings

Because they are everywhere, they can easily enter the food chain and the human organism via food and drink. When and where this happens, however, is difficult to ascertain and has barely been researched. “After all,” says Michael Siegrist, a professor at the Institute of Environmental Decisions at ETH Zurich, “often you don’t know where in the food chain the phthalates get into the food – whether they come from the bucket used to harvest olives, the conveyor belt, or elsewhere in the production chain”.

Consequently, Siegrist supervised a study at the Institute of Environmental Decisions in conjunction with the Institute of Chemistry and Bioengineering at ETH Zurich which showed that sensible eating cannot really prevent the intake of phthalates. As a matter of fact, consumers who eat naturally and healthily and try to keep the chemical additives in their food to a minimum might even be ingesting more phthalates on a daily basis than those who do not worry about their diet at all.

On the one hand, the study was aimed at assessing consumers’ eating habits to show the extent to which they are exposed to phthalates. On the other hand, however, the scientists examined the relationship between the consumers’ exposure and their interest in a natural and healthy diet, as well as their risk perception of chemicals in food, such as pesticides or phthalates, such as with pesticides or phthalates. For the first time, the scientists thus established a link between consumer perception and physical reality as regards the intake of food containing phthalates.

In their study, the research team polled about 1200 people in German-speaking Switzerland about their eating habits. The respondents were asked to provide information on their diet. The evaluation of the survey yielded four characteristic groups: people who eat health-consciously and also rely on vitamin supplements compared to those who eat healthily and naturally, people who do not worry about their food and react passively, and people who consume an especially high amount of fatty and sugary food and ready-to-eat meals.

Junk food no worse than healthy products

To quantify the phthalate amounts ingested by the test people in their food, the researchers used existing data for food where the phthalate exposure had already been examined. It became clear that the people who have a healthy and natural diet ingest most of some phthalates, whereas those who behave more passively in their eating habits are the least exposed to the pollutants. All in all, the results of the two nutritionally aware groups and the “fatty, sugary and ready-to-eat meals” group were similar. However, it seems reassuring that the various tolerance levels issued by the European Food Safety Agency for different softening agents did not even come close to being reached in the study, let alone exceeded. Nevertheless, the researchers admit that the result should be taken with a pinch of salt as not all foods could be taken into account.

All the same, the result seems ironic and the researchers are also at a loss to explain why. Maria Dickson-Spillmann, Siegrist’s doctoral student and first author of the study, stresses that the matter still needs a lot of research. She says, “Our results show that even consumers who make a point of having a healthy and natural diet cannot escape chemical pollutants like phthalates. The findings underline the importance of food controls by cantonal laboratories”. Nonetheless, it would be wrong to advise consumers against fresh fruit and vegetables, for example, as this may cause other health risks.

In recent years, various studies have suggested that phthalates act like hormones in humans: above all, deformities in the genital area in male offspring became apparent. However, additional but still debatable links to sterility and diabetes in men, premature births in pregnant women and premature breast development in girls were also established. Consequently, teething rings for babies without phthalates are now being promoted, for instance, and the food industry is using rubber gloves and packaging materials that hardly emit any phthalates, or do not contain any at all. That said, due to their omnipresence, it is highly unlikely that they can be eliminated from the food chain altogether.