If you haven’t been living under a rock, you’ve probably heard that wild-caught salmon is widely considered to pack more nutritional (and environmental) benefits than farm-raised salmon. But considering the significantly heftier price tag on wild-caught, how much of a nutritional difference are we really talking about here?
If the difference is only negligible, is the more-affordable farmed salmon still a good choice? Here’s what registered dietitians and environmental sustainability experts have to say.
What’s the difference in how they’re raised?
It’s important to understand that farmed salmon and wild salmon have some distinct differences. Wild salmon live in oceans, rivers and streams, and typically travel far distances and eat a diet of smaller fish and marine organisms. Farmed salmon are raised in controlled environments like tanks, net pens and other enclosures for the specific purpose of being eaten, and are fed pellets made of fish oil, fishmeal, plant proteins, vitamins and minerals.
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How nutritious is farmed salmon?
Farmed salmon is a nutrient-dense food that offers health benefits similar to wild salmon, although there are some key differences between the two. Farmed salmon is generally higher in fat than wild salmon, but it’s also loaded with heart-healthy omega-3 fatty acids, protein, vitamins and minerals. Here’s a breakdown of some of salmon’s key nutritional benefits:
Salmon, in general, like other fatty fish, is one of the best food sources of the heart-healthy omega-3 fatty acids EPA and DHA. In fact, fatty fish like salmon, mackerel and sardines are so good for heart health that the American Heart Association recommends eating at least two three-ounce servings each week.
“Omega-3 fatty acids can help reduce inflammation in the body, support the immune system, and lower high blood pressure,” said Joan Salge Blake, a registered dietitian and clinical professor of nutrition at Boston University. “Chronically high blood pressure increases the risk of stroke and heart disease.”
The exact amount of omega-3s in farmed salmon varies depending on the type, what it eats and how it’s farmed, butfarmed usually contains more thanwild. “This is due to its higher total fat content, which includes more of the beneficial EPA and DHA omega-3s,” saidRomy Nathan, a registered dietitian specializing in cardiometabolic health and diabetes. Numbers will vary depending on source, but according to USDA FoodData Central,a 3-ounce serving of farmed salmon contains about 10.5 grams of fat compared to about 7 grams of fat in a 3-ounce serving of wild salmon. Farmed salmon is typically slightly higher in saturated fat, as well, containing 2 grams of saturated fat per serving compared with 1 gram of saturated fat per serving in wild salmon.
Vitamin D
Salmon is a great source of vitamin D — a nutrient that supports bone health, immune health and more. But all salmon isn’t the same when it comes to vitamin D content.
Research shows that wild salmon tend to have more vitamin D than farmed salmon. And even among farmed salmon, the vitamin D content varies greatly from one variety to another, likely due to the food that the salmon eats. “Wild salmon can have substantially more vitamin D because they are feeding on krill and small fish,” Nathan said. “In contrast, farm-raised salmon are dependent on the composition and fortification of the feed provided.”
While wild salmon tends to be much richer in vitamin D than farmed salmon, the exact amount varies depending on where the fish comes from. In a 2019 study published in the journal ”Nutrients,” wild salmon caught in the Baltic Sea contained about 18.5 micrograms (µg) of vitamin D per 100 grams of fish (that’s roughly a 3.5-ounce serving). Meanwhile, wild salmon from the North Sea had about half that — 9.4 µg per 100 grams. By comparison, farmed salmon contained anywhere from about 3 to 9.5 µg per 100 grams. The recommended dietary allowance (RDA) for vitamin D for adults under 70 is 15 mcg, or 600 IU.
Protein
Another reason to eat salmon is its protein content. Like wild salmon, farmed salmon is a high-quality protein source, which helps with immune functioning, muscle growth and repair, satiety and energy.
In a 3-ounce serving of farmed salmon, you’ll get nearly 19 grams of protein. This is slightly less than the nearly 22 grams you’ll get in a serving of wild salmon, though the amounts vary depending on the specific type of salmon and where it’s sourced.
Are there contaminants and antibiotics in farmed salmon?
You may have heard that farmed salmon contains high levels of potentially harmful contaminants like polychlorinated biphenyls (PCBs), which can accumulate in the bodies of fish, according to the Environmental Protection Agency.
“Since PCBs are stored in fat, the fattier farmed fish may carry more contaminants than the wild salmon, which are leaner and have been less exposed through the food they naturally consume,” Nathan said. However, many governments, including the United States, have set regulatory limits requiring that salmon produced in these regions do not exceed certain levels of PCBs.
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Depending on where your farmed salmon is sourced and the practices of the fish farm, its feed may contain antibiotics. These, along with pesticides, are sometimes used to prevent infections that can easily spread in crowded pens. But those same antibiotics can have a negative impact on the environment and human health, including an increased risk of antibiotic resistance and gut health problems. Many governments, including the United States, Canada and Norway, regulate and limit antibiotic use in aquaculture, but others do not, so you may want to pay attention to where your salmon came from (hang tight — we’ll outline some helpful resources for that in the next section).
Is farmed salmon environmentally sustainable?
According to environmental sustainability experts, it depends. “From an environmental perspective, farmed salmon isn’t inherently good or bad — it depends entirely on how it’s farmed,” said Jennifer Bushman, a sustainable seafood expert and executive director of Fed by Blue.
Salmon farming tends to come with a number of environmental drawbacks, including pollution, overcrowding, transfer of disease to wild salmon populations, and unsustainable sourcing of feed. “The majority of farmed salmon today is not raised under environmentally responsible or ethical conditions,” Bushman added.
Still, there are some salmon farms out there operating more responsibly. “Kvarøy Arctic is a great example — they are a third-generation family farm in the strong, cold currents of Norway’s Arctic Circle, with low stocking densities, no antibiotics, and a focus on sustainable feed,” Bushman said. “Ōra King, in New Zealand, is another standout. They raise king salmon with incredibly high environmental and welfare standards, and you can taste the difference.”
Keeping an eye out for certification labels from trusted third-party groups can be helpful if you’re looking to be environmentally conscious as you shop. These let you know the product meets sustainability standards.
“Look out for the Marine Stewardship Council logo or the Aquaculture Stewardship Council logo on fish that you buy,” said Jennifer Brandon, an oceanographer and science communications expert. Another high-quality, helpful resource for determining if the fish meets sustainability standards is the Monterey Bay Aquarium’s Seafood Watch, which rates salmon and other fish into simple categories, including “Best Choice,” “Good Alternative,” “Avoid,” and “Certified.”
So, should you eat farmed salmon or not?
From a nutrition or cost perspective, farmed salmon can be a solid food choice with numerous potential health benefits. “Cold water fish, such as salmon, is often considered a superfood because of its high nutrient content for the calories it provides,” Nathan said. “Wild salmon may be higher in vitamin D, lower in calories, and lower in saturated fat, [but] farm-raised salmon can still pack a nutritious punch worth your money, especially when sourced from responsibly managed farms.”
As she noted, the environmental concerns of many salmon farming operations are also worth considering. “When buying farmed fish, look for those that are grown using sustainable practices,” Salge Blake said. “The Monterey Bay Aquarium Seafood Watch is a wonderful guide to help consumers know where to buy sustainable seafood.”
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