Microplastic intake through diet?
Study suggests an association to the degree of food processing
What influence does diet have on oral microplastics intake? The Umweltbundesamt - Environment Agency Austria has investigated this question in a pilot study with 15 participants. The results were published recently in the scientific journal Science of the Total Environment. The study suggests that a higher degree of food processing may have an influence on the intake of microplastics.
15 volunteers from Vienna and the surrounding area aged 24-43 participated in the intervention study for 16 days. On several consecutive days, they consumed food with as less plastic contact as possible as well as food with as much plastic contact as possible. For this, food packaging and kitchen utensils were considered. The participants also consumed food with different levels of processing, from unprocessed food to ready meals. Over the entire intervention period, the participants recorded their food and drinks consumed, the packaging and the preparation. Four stool samples per person were collected and analyzed. The study was funded by Plastics Europe, the European association of plastics producers, as part of a comprehensive research project.
Microplastics were detected in all stool samples, with most frequently polyethylene and PET found.
Microplastics were analyzed in the participants' stool by the Umweltbundesamt laboratory. Ten of the globally most common plastic types with particles sizes ranging from 5 µm to 5 mm were examined. At least one plastic type was detected in all samples analyzed, with the exception of polycarbonate (PC), which was not detected in any of the samples. On average, 3.4 microplastic particles were found per gram stool. The most frequently detected plastic types were polyethylene (PE) and PET. PE is the most commonly used type of plastic worldwide and is used in particular for food packaging. PET is also used for food packaging and in many other consumer products such as textiles.
Microplastic concentrations higher in higher processed foods
With the pilot study, the Umweltbundesamt experts wanted to clarify whether the use of more or less plastic in the diet has an influence on the oral intake of microplastics. A significant difference between a low plastics exposure scenario and a high plastic exposure scenario was not clearly identified. However, it was found that the degree of food processing seems to play a relevant role. For example, participants showed higher microplastic concentrations in their stool when consuming higher processed food. For the Umweltbundesamt experts, the pilot study provides important evidence on the influence of the degree of food processing on microplastic intake. According to the study authors, a larger study could clarify a clear connection.
The results support international studies and assumptions on microplastic intake in association with the degree of food processing. For example, the European Food Safety Authority (EFSA) pointed out in 2016 that the amount of microplastics might increase during food processing.
