As many people try to improve their diet by cutting down on red meat, fish seems like a good healthy option. However, the sustainability of eating fish has increasingly been called into question. Here, we investigate the health claims and arguments for and against eating fish and explore some alternatives. Fish can be an important source of key nutrients, but can we eat fish sustainably? We investigate. (Pictured: Aerial shot above a circular fish farm in a loch, Scottish Highlands, United Kingdom.) Image credit: Abstract Aerial Art/Getty Images.
Some people consider fish to be a healthy alternative to red meat. It is a good source of protein, omega-3 and omega-6 fatty acids, and several minerals and vitamins. Omega-3 fatty acids, which, as research has shown, can have a positive effect on heart health, are present in high concentrations in oily fish, such as salmon and mackerel. Research indicates these fatty acids can also promote greater blood flow to the brain, which is vital for delivering oxygen essential for brain function. And one study has suggested that omega-3s may have a role in healthy brain aging trusted Source.
Eating fish may also combat inflammation: a recent study found that regular consumption of fish helped reduce the incidence of chronic inflammatory conditions and may even benefit the immune systemTrusted Source. Medical News Today spoke to Kate Cohen, MS, RDN, for the Elli- son Clinic at Providence Saint John’s Health Center in Santa Monica, CA, to find out the science behind some of these claims. “Fish and shellfish are the main sources in our diet of the polyunsaturated fats, DHA [docosahexaenoic acidTrusted Source] and EOA [eicosa- pentaenoic acid], which are associated with brain development in pregnancy and linked to a number of potential overall health benefits,” she said. But not all fish are equal. “Cold-water fish have a higher amount of fat to keep the fish warm in icy waters, but this also loads the fish with beneficial omega-3 and omega-6 fatty acids,” she added.
However, there are some concerns about the high levels of mercuryTrust- ed Source in some of these cold-water fish. Suitable options with high concentrations of beneficial fatty acids and low mercury levels are wild salmon, sardines, rainbow trout, and Atlan- tic mackerel. And what of white fish and shellfish? Lower in calories than oily fish, they do not contain high lev- els of omega-3 but are a good source of lean protein and many minerals and vitamins, such as iron, zinc, and vitamins A, B12, and D.
Cohen recommended including fish in your diet 2–3 times a week to get the benefits but advised that you “rotate your fish. Your body needs all the different vitamins and minerals available in fish, so don’t stick with just one kind.” Is wild-caught fish sustainable? hocking images of waste, environmental- mental pollution, and bycatch (catch- ing a species of fish or marine species unintentionally), including marine mammals, turtles, and seabirds, have led many to question whether the health benefits of fish and seafood are worth the environmental costs. The Marine Stewardship Council (MSC) sets the standard for sustainable fisheries worldwide, with organizations such as Monterey Bay Aquarium Seafood Watch fulfilling a similar role in the United States. The MSC refutes the claim that there is no such thing as sustainable fishing, outlining three principles for sustainable fisheries: sustainable fish stocks, minimizing environmental impacts, and effective fisheries management.
The MSC states that “fish stocks can recover and replenish if they are managed carefully for the long-term.” Its website includes a list of fish that are sustainable when they carry the MSC label. In the U.S., the Washington- based Environmental Working Group (EWG) goes further, giving a regularly updated list of fish that are both healthy — in terms of contaminant levels — and sustainable. Similar information is listed on the U.S. government’s Fishwatch. Josep Lloret, Director of Oceans and Human Health Chair at the University of Girona, Spain, agreed that sustainable fishing is possible but challenging: “Artisanal (small scale) fisheries are seen as the most sustainable, but even these have their own environmental footprints, such as the impact on vulnerable species due to selectivity issues.” “Marine Protected Areas (MPAs) can be effective if they are well implemented and well managed. However, many MPAs around the world lack a proper management plan,” he added. There is some good news. According to the European Environment Agency, there are signs of recovery in the North-East Atlantic Ocean and the Baltic Sea.
However, it states that further collective action is necessary to regain healthy commercial fish and shellfish populations in European waters. In the U.S., despite overfishing, some stocks are starting to recover because of the careful management of fisheries. “Seafood is a healthy option compared to meat, but if we follow doc- tors’ recommendations of omega-3 fatty acid intake, with the expected rise of the human population, we will very quickly deplete our seas.” What is the alternative?
So, if wild fish stocks cannot supply the amount of fish needed for optimal intake of fatty acids, where can the fish originate? An obvious alternative to wild-caught fish is fish farming or aquaculture. There are no issues with bycatch, the fish is cheaper to buy, the supply is more reliable, and there is less effect on wild habitats. But is farmed fish as good for us as wild-caught fish? “It really comes down to what the fish eats and its environment,” said Cohen. “Farmed salmon, for example, can have about 40% more calories than wild salmon and about 50% more fat — which is a pretty huge difference.” She added that “there is also a greater risk of contaminants in farm-raised fish that are kept in small, enclosed pens, as well as antibiotic exposure from the farms’ attempts at disease prevention.” There is also concern about the food that these farmed fish eat. Josep Lloret commented: “Farmed fish have several problems, including the need for forage fish to feed them (then the for- age fish get overexploited), compared to land, we raise ‘lions’ at sea (predators, such as sea bass, that consume a lot of forage fish), [and there is] impact on sea bottoms because of pollution.”
Pollution concerns
One way of minimizing this pollution is by combining different types of aquaculture, as outlined in a 2020 report by the Food and Agriculture Organization of the United Nations (FAO). If fish farmers grow an extractive species, such as filter-feeding mussels, near fish pens, the mussels remove the waste from the water. And those bivalves are nutrient-rich, low-mercury seafood themselves. Organizations, such as the Aquaculture Stewardship Council, promote responsible aquaculture and provide certification for farms that meet their standards through independent in- spections. And fish farming organizations are looking at alternatives to fish-based feeds, such as soy, canola, and seaweed.
