An Examination of the n-3 and n-6 Polyunsaturated Fatty Acid Status of Wild and Farmed Atlantic Salmon (Salmo salar)

Salmon are a good dietary source of n-3 polyunsaturated fatty acids (PUFAs) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) which may be effective in the prevention and treatment of ischaemic heart disease. This study has shown that while n-3 PUFA levels vary widely depending on the fat content of the fish, there was no significant difference between wild and farmed salmon as sources of these acids with both types producing around 1g per 100g of fish consumed. The ration of n:3 to n:6 PUFAs was on average 6-fold higher in the flesh oil of wild salmon than in farmed fish due to the use of linoleic acid (n-6) rich vegetable oil in the diet of the latter. PUFA analysis of fat extracted from a range of feeds used in the production of a majority of the farmed fish studied showed them to be based mainly on n-3 fish oils with a relatively low incorporation of vegetable oil. The n-3 PUFA levels of salmon were found to be largely unaffected by smoking.