Can human nutrition be improved through better fish feeding practices? a review paper

Achieving Sustainable Development Goal 2 of zero hunger and malnutrition by 2030 will require dietary shifts that include increasing the consumption of nutrient dense foods by populations in low- and middle-income countries. Animal source foods are known to be rich in a number of highly bioavailable nutrients that otherwise are not often consumed in the staple-food based diets of poorer populations throughout the world. Fish is the dominant animal source food in many low- and middle-income countries in the global south and is available from both fisheries and aquaculture. Consumers often perceive that wild caught fish have higher nutritional value than fish produced through aquaculture, and this may be true for some nutrients, for example omega-3 fatty acid content. However, there is potential to modify the nutritional value of farmed fish through feeds and through production systems, illustrated by the common practice of supplementing omega-3 fatty acids in fish diets to optimize their fatty acid profile. This manuscript reviews the evidence related to fish feeds and the nutritional composition of fish with respect to a number of nutrients of interest to human health, including iron, zinc, vitamins A and D, selenium, calcium, and omega-3 fatty acids, with low- and middle-income country populations in mind. In general, we find that the research on fortification of fish diet particularly with vitamins and minerals has not been directed toward human health but rather toward improvement of fish growth and health performance. We were unable to identify any studies directly exploring the impact of fish feed modification on the health of human consumers of fish, but as nutrition and health rises in the development agenda and consumer attention, the topic requires more urgent attention in future feed formulations.