Dietary intake of differently fed salmon: a preliminary study on contaminants


  • National Institute of Nutrition and Seafood Research (NIFES), Bergen (C. Bethune, L. Frøyland, A-K. Lundebye); Department of Basic Sciences and Aquatic Medicine, The Norwegian School of Veterinary Science, Oslo (S. L. Seierstad); Center for Clinical Research (I. Seljeflot, H. Arnesen) and Department of Cardiology (O. Johansen, H. Arnesen), Ullevaal University Hospital, Oslo; Department of Food Toxicology, Division of Environmental Health, Norwegian Institute of Public Health, Oslo (H. M. Meltzer); Nutreco Aquaculture Research Centre, Stavanger (G. Rosenlund), Norway.

Claudette Bethune, PhD, National Institute of Nutrition and Seafood Research, PO Box 2029 Nordnes, 5817 Bergen, Norway. Tel.: +47 55905129; fax: +47 55905299; e-mail:


Background  In a previous study, a group of coronary heart disease (CHD) patients exhibited positive cardioprotective effects of fatty acids derived from a diet of farmed Atlantic salmon fed fish oil (Seierstad et al. 2005). This follow-up study examines these patients for plasma exposure to selected organic and inorganic contaminants found in seafood that may detract from the benefits of eating oily fish.

Methods  The study design was from Seierstad et al. (2005), where 58 patients were allocated into three groups consuming 700 g week−1 of differently fed Atlantic salmon (Salmo salar) fillets for 6 weeks: 100% fish oil (FO), 100% rapeseed oil (RO), or 50% of each (FO/RO).

Results  Different fillets showed graded levels (FO > FO/RO > RO) of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (DLPCBs), indicator PCBs, polybrominated diphenyl ethers (PBDEs), and arsenic (As). Mercury (Hg) and lead (Pb) levels were similar across the three types of fillets. After 6 weeks of consumption, patient levels of PCDDs, DLPCBs, and PCBs in plasma decreased as the dietary intake of these contaminants increased. Plasma PBDEs only showed increases for the FO patients. Levels of inorganic contaminants in plasma showed only slight changes over the study period.

Conclusions  These results show a reduction in the use of marine oils in fish feed reduces organic contaminant levels in farmed salmon while still providing a good dietary source of marine fatty acids.