It is widely known that regularly eating oily fish like salmon is beneficial to human health because it is packed with protein and is good for the heart. However, many wild marine fishing areas are suffering from severely depleted fish stocks, hence farmed fish — or aquaculture — is on the rise.

Today, farmed fish account for around half of all fish consumed in the world.

One European Union-funded project has delved into how to make farmed fish even healthier via the food the fish eat, potentially boosting the global competitiveness of EU salmon.

OMEGA3MAX has produced novel scientific knowledge on the use of antioxidants such as polyphenols in Atlantic salmon diets. Polyphenols are a type of chemical found naturally in many healthy foodstuffs, including fruit, vegetables, green tea, spices and olive oil. It is believed that eating them can help prevent degenerative diseases such as cancer and cardiovascular diseases.

In its project results, OMEGA3MAX conceded that much remains to be done to fully implement the use of new antioxidant sources in Atlantic salmon. However, the project has created a knowledge base that paves the way for the use of some natural antioxidants, including polyphenols.

"In this project, we have shown that we can enrich salmon fillet with antioxidants such as gamma-tocopherol — a vitamin E isomer with important antioxidant and anti-inflammatory properties," OMEGA3MAX project coordinator Dr. David Menoyo Luque said.

Boosting the aquaculture industry

OMEGA3MAX is also hoping that its findings will have practical applications in the aquaculture industry.

"If farmed fish have optimal husbandry conditions, good health and adequate feed that is well-suited to the physiological needs of the farmed animals, then growth and production levels will be boosted to the benefit of the industry," Menoyo explained.

The project set out to discover ways to boost the health and health-giving properties specifically of farmed salmon.

"Farmed fish such as Atlantic salmon are a rich source of healthy long-chain polyunsaturated fatty acids, including the marine eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), high-quality protein, vitamins A, B12, D and E and minerals like iodine and selenium," Menoyo added.

While these health properties are established, scientific advances are showing how to enrich the particularly good nutrients and diminish ones that have been raised as a concern.

"The scientific community has been trying to identify important health-promoting compounds found in food. Recent advances in animal production technologies and practices, like those used in our project, have shown that it is possible to increase the concentration of these compounds in animal tissue to boost the nutritional value for the consumer," he added.

OMEGA3MAX tested 12 different antioxidant substances on farmed Atlantic salmon. Of these, one was found to enhance the concentrations of the omega-3 fatty acids EPA and DHA in fish fillets compared to fish not fed the antioxidant supplement.

"Our project can help the industry develop novel, cost-effective feeding strategies that can support the sustainable development of the EU’s aquaculture industry," Menoyo concluded.