Wild caught fish, especially marine fish, may contain high levels of persistent organic pollutants (POPs). In the Netherlands, especially eel from the main rivers have high POP levels. This led to a ban on eel fishing in 2011 due to health concerns. We showed that men consuming eel from the high-polluted areas indeed have elevated levels of dioxins and dioxin-like compounds, polychlorinated biphenyls (PCBs), and perfluorinated compounds.
Epigenetic phenomena, such as DNA methylation, have been proposed as a possible molecular mechanism underlying adverse health effects. We detected aberrant DNA methylation in differentiating adipocytes upon POP-exposure in vitro. In male eel consumers with elevated POP levels we identified differentially methylated regions in genes involved in carcinogenesis or the immune system.
We conclude that the consumption of eel from high-polluted areas leads to accumulation of POPs above safe levels and that these POP levels are associated with gene-specific DNA methylation.