In an article published on January 26, 2022, in the peer-reviewed journal Environmental Science & Technology, Johannes Völker from the Norwegian University of Science and Technology (NTNU), Trondheim, Norway, and co-authors investigated chemicals contained in plastic products for their adipogenic activity, i.e., promotion of obesity. For their study, the researchers selected 34 plastic products with and without food contact and made of several polymer types that had been previously assessed for their unspecific toxicity and endocrine activity (FPF reported). Upon extraction experiments with methanol, they applied the samples to an in vitro adipogenesis assay with murine 3T3-L1 cells and nontarget high-resolution mass spectrometry (LC- QTOF-MS/MS).
Völker et al. reported that one-third of the samples induced adipogenesis. The products made of polyvinyl chloride (PVC) and polyurethane (PU) most consistently contained chemicals with adipogenic activity, while those made of polyethylene terephthalate (PET), high-density polyethylene (HDPE), and polylactic acid (PLA) did not induce an adipogenic response. To evaluate the mechanism underlying the response, Völker and co-authors further tested the extracts’ activity at the human peroxisome proliferator-activated receptor gamma (PPARγ) and glucocorticoid receptor (GR) since these receptors are key regulators of adipogenesis and lipid metabolism, respectively. However, most extracts did not activate these two receptors. Thus, the scientists believe that other mechanisms induce the adipogenic effects, which still need to be explored.
Concerning the chemical composition of the plastic extracts, Völker et al. detected over 55,000 chemical features in the 34 samples of which they tentatively identified 629 compounds. A comparison with known metabolism-disrupting chemicals (MDCs) showed that 11 of the 629 are known MDCs. These included four phthalates and six organophosphates. The authors concluded “that daily-use plastics contain potent mixtures of MDCs and can, therefore, be a relevant yet underestimated environmental factor contributing to obesity.”
Previously, researchers have reported that some endocrine-disrupting chemicals may contribute to the increase in metabolic disorders, including obesity (FPF reported), and they have observed a correlation between exposure to bisphenol A (BPA, 80-05-7), bisphenol S (BPS, 80-09-1), and bisphenol F (BPF, 620-92-8) with childhood obesity in particular (FPF reported).
Reference
Völker, J. et al. (2022). “Adipogenic Activity of Chemicals Used in Plastic Consumer Products.” Environmental Science & Technology. DOI: 10.1021/acs.est.1c06316
Read more
Adrienne Matei. (2022). “Plastics touching our food may be making us gain weight.” The Guardian
