Eating farmed salmon brings measurable benefits to people that have been diagnosed with coronary heart disease (CHD) and the higher the content of marine omega-3 in the feed on which the salmon were raised, the better it is for the cardiac patients. These are conclusions of a Norwegian research project involving Ullevål University Hospital in Oslo, Norwegian National Institute of Nutrition and Seafood Research (NIFES) in Bergen and Nutreco Aquaculture Research Centre (ARC) in Stavanger. The Norwegian Research Council also supported the project.

Monday 30 August the results will be presented at the European Society of Cardiology’s 2004 Congress in Munich, Germany.

The study began in 2003 with the recruitment of 60 CHD patients of the Ullevål University Hospital, Norway’s leading medical research centre. Before the six-week eating trial began the blood of all patients was analysed for a series of medical indicators (the serum fatty acid profile, lipoproteins and key markers of arteriosclerosis). These indicators were re-checked following the trial, to assess the extent of any changes.

Patients were randomly divided into three groups of 20. Each group was given salmon raised on diets with high, standard or basic levels of omega-3 fatty acids. Throughout the six-week trial each patient ate five salmon meals a week, totalling 700g of salmon a week.

Analysis of the blood samples taken at the end of the trial showed lower cholesterol levels in all three groups of patients, but less improvement in the high marine omega-3 group. On the other hand, eating salmon fed on the high marine omega-3 diet resulted in the best improvements for the other markers.

The highest omega-3 level was obtained in salmon given a feed with 100% fish oil. Diet number two was based on 50% fish oil and 50% rapeseed oil and the basic diet used only vegetable oil. Even this basic omega-3 diet gave the cardiac patients some 15 times the amount of omega-3 than would be derived from eating most meats.

The results of this trial add to those of many other published research projects to show that omega-3 fatty acids, derived from eating oily fish such as salmon, do have health benefits. The CHD patient trial also indicates a potential medical role for fish with very high-levels of marine omega-3 fatty acids.

In addition to the work at Ullevål University Hospital, Nutreco ARC was also looking at the effect new raw materials have on fish health and nutritional content.

Extensive studies to date show that vegetable oils containing omega-3 can quite easily substitute some of the fish oil in the feed. The salmon remains the same safe and healthy delicacy with the correct salmon taste and with beneficial levels of heart-friendly omega-3 fatty acids.

Alternative feed resources

This is the first time cardiac patients have been directly involved in a project related to the formulation of salmon feed, however, Nutreco ARC believes that such thoroughness is essential in the continuing search for new raw materials for salmon feed. A prerequisite for continued growth in the fish farming industry is that there are sustainable resources for feed raw materials, but the supply of marine-origin materials is potentially limited. Therefore alternatives are being implemented.