Polychlorinated biphenyls (PCBs) contamination and aryl hydrocarbon receptor (AhR) agonist activity of Omega-3 polyunsaturated fatty acid supplements: implications for daily intake of dioxins and PCBs

Food Chem Toxicol. 2010 Nov;48(11):3093-7. doi: 10.1016/j.fct.2010.07.051. Epub 2010 Aug 6.


Omega-3 polyunsaturated fatty acid (n-3 PUFA) rich oils derived primarily from fish are frequently consumed as supplements. Due to the tendency of persistent organic pollutants (POPs) to accumulate in exposed organisms, n-3 PUFA supplements can contain sufficient POPs to present a risk to consumers. Here we investigated PCB concentrations and aryl hydrocarbon receptor (AhR) agonist activity in 17 n-3 PUFA supplements available in Canada. PCBs ranged from <0.8 to 793 ng g(-1) oil, with salmon- and seal-derived products yielding the highest values. AhR agonist activity from a reporter gene assay ranged from 1.3 to 72.2 pg TEQ g(-1) oil, with salmon and tuna yielding the highest values. When consumed at the recommended doses and as a supplement to the average Canadian diet, seal-derived oil can contribute to exceedance of the tolerable daily intake of 20 ng PCBs kg-BW(-1)day(-1), and salmon-, tuna-, and sea herring-derived oils can contribute to exceedance of the tolerable daily intake limit of 2.3 pg TEQ kg-BW(-1)day(-1). The beneficial properties of fish and n-3 PUFA supplements, and the results of this study suggest that it is prudent to consume supplements derived from small, cold-water fatty fish. Further research will be necessary to draw firm conclusions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / agonists*
  • Cell Line, Transformed
  • Chromatography, Gas
  • Chromatography, Gel
  • Dietary Supplements / adverse effects*
  • Dietary Supplements / analysis
  • Dioxins / analysis*
  • Dioxins / toxicity
  • Environmental Pollutants / analysis*
  • Environmental Pollutants / toxicity
  • Fatty Acids, Omega-3 / administration & dosage*
  • Fish Oils / chemistry
  • Food Contamination / analysis*
  • Hepatocytes / drug effects
  • Hepatocytes / enzymology
  • Humans
  • Luciferases / metabolism
  • Maximum Allowable Concentration
  • Mice
  • Polychlorinated Biphenyls / analysis*
  • Polychlorinated Biphenyls / toxicity
  • Receptors, Aryl Hydrocarbon / agonists*


  • AHR protein, human
  • Basic Helix-Loop-Helix Transcription Factors
  • Dioxins
  • Environmental Pollutants
  • Fatty Acids, Omega-3
  • Fish Oils
  • Receptors, Aryl Hydrocarbon
  • Polychlorinated Biphenyls
  • Luciferases