Scientists have discovered that salmon might not be as nutrient-dense as previously thought and have identified the type of fish that is best for human health.

Researchers from the Universities of Cambridge, Lancaster, Stirling, and Aberdeen have revealed that the production of farmed salmon results in the loss of six of the nine minerals (iron, calcium, iodine, omega-3, vitamin B12, and vitamin A). Their findings were published in the journal Nature Food.

Actually, the wild species that are given to salmon—like mackerel, anchovies, and herring—are the ones we should be selecting. These fish are rich in minerals like calcium, omega-3 fatty acids, and vitamin B12.

“What we’re seeing is that most species of wild fish used as feed have a similar or greater density and range of micronutrients than farmed salmon fillets,” the lead author of the study, David Willer of the Zoology Department at the University of Cambridge, said in a summary of the findings.

The study’s lead author, David Willer of the University of Cambridge’s Zoology Department, summarized the findings by saying, “What we’re seeing is that most species of wild fish used as feed have a similar or greater density and range of micronutrients than farmed salmon fillets.”

“Whilst still enjoying eating salmon and supporting sustainable growth in the sector, people should consider eating a greater and wider variety of wild fish species like sardines, mackerel and anchovies, to get more essential nutrients straight to their plate.”

The study discovered that the amount of calcium in wild feed fish fillets was five times higher than that in salmon. In addition, they found that the level of iodine, iron, omega-3, vitamin B12, and vitamin A was four times higher than what was observed in the salmon fillet alone. Nonetheless, they discovered that the salmon had higher selenium and zinc levels.

These wild-feed fish’s nutrients aid in the prevention of diseases like stroke and cardiovascular disease.

“We’re effectively wasting around 80% of the calcium and iodine from the feed fish – especially when we consider that women and teenage girls are often not getting enough of these nutrients,” added Richard Newton, who led the research team at the University of Stirling’s Institute of Aquaculture. Other team members included Professor Dave Little, Björn Kok, and Wesley Malcorps.

“Farmed salmon is an excellent source of nutrition, and is one of the best converters of feed of any farmed animal, but for the industry to grow it needs to become better at retaining key nutrients that it is fed. This can be done through more strategic use of feed ingredients, including from fishery by-products and sustainably-sourced, industrial-grade fish such as sand eels.”

Additionally, compared to farmed salmon, fish fed wild was found to supply these nutrients in lesser amounts. It was discovered by researchers that eating one-third of wild-feed fish could increase our intake of local nutrients.

“Making a few small changes to our diet around the type of fish that we eat can go a long way to changing some of these deficiencies and increasing the health of both our population and planet,” Willer said.

Large catches are being redirected into agricultural feeds, according to Lancaster University senior author James Robinson, despite the importance of marine fisheries to regional and global food systems.

“Prioritizing nutritious seafood for people can help improve both diets and ocean sustainability,” Robinson stated.

The study’s recommendations may be able to alleviate “global nutrient deficiencies,” according to the scientists.