Reevaluating the Health Profile of Farmed Salmon

Summary: Farmed salmon contains high levels of saturated fat, and more calories than wild salmon. It can also be contaminated with microplastics, chemicals like PCBs, and antibiotic-resistant bacteria, posing risks to both consumers and ecosystems. With certifications offering limited protection and misleading "organic" labeling, the significant health and environmental concerns surrounding farmed salmon warrant careful consideration.

‍

Farmed salmon is marketed as a healthy choice, a better alternative to beef, pork and poultry. But questions about its nutritional value and farming-related contaminants have farmed salmon under increasing scrutiny.

Nutritional profile: More fat, fewer benefits

Farmed salmon contains troubling levels of saturated fat — more than double that of wild salmon.¹²

While it may boast higher omega-3 fatty acid content due to artificially enriched feed, the Cleveland Clinic warns that this benefit is overshadowed by the risks associated with its elevated saturated fat, which can contribute to heart disease.¹

A three-ounce fillet of farmed salmon also has significantly more calories and overall fat than its wild counterpart.¹,²

Microplastics: A widespread contaminant

Microplastics are a pervasive contaminant in farmed salmon. One 2020 study found farmed fish are far more likely to contain them than wild fish, with particles embedded in their gill tissues.⁴ Microplastics pose a threat to human health. A recent review of scientific evidence concluding that they are suspected to “harm human reproductive, digestive, and respiratory health, with a suggested link to colon and lung cancer.”¹⁸

One source of microplastics in sea cages is the result of friction in plastic feed pipes, which release particles into the water.⁶ Research from the National Institute of Standards and Technology in 2023 found that this exposure to microplastics also weakens fish, increasing mortality rates when combined with viral infections.³ This finding further underscores concerns of potential health impacts on human consumers.

Chemical contaminants: High levels of toxic pollutants

Studies in 2019 and 2022 found that farmed salmon absorb and retain harmful pollutants such as PCBs (polychlorinated biphenyls) at levels 16 times higher than wild salmon.¹⁷,⁵

These persistent organic pollutants (POPs) are linked to obesity, type 2 diabetes and an increased risk of stroke, particularly in women.¹⁷,⁵

‍Antibiotic Resistance: A Growing Global Threat

The widespread use of antibiotics in salmon farming raises red flags for global public health.

Farmed salmon are often raised in overcrowded, unsanitary conditions that breed disease and necessitate antibiotic use. Even after fish are “purged” of antibiotics, this misuse leads to the emergence of antibiotic resistant bacteria, which pose a direct threat to human health.⁷,⁸,⁹,¹⁰

Resistant genes from aquaculture bacteria can transfer to human pathogens, increasing the risk of untreatable infections and "superbugs."⁷,⁸,⁹,¹⁰

Studies in 2024 found that Chilean salmon farms, for example, are hotbeds of antibiotic resistant bacteria.¹¹

Global warming is likely to exacerbate this crisis by increasing disease and death in sea cages, thereby driving up antibiotic usage and further accelerating the spread of resistance.⁷,⁸,⁹,¹⁰,¹¹

Antibiotic residues in aquatic environments also pose risks to marine ecosystems, creating reservoirs of resistance that also have the potential to eventually impact human populations.⁷,⁸,⁹,¹⁰,¹¹

Label this 'confusing'

It is difficult to find out what has gone into raising farmed salmon due to the lack of transparency in labeling and the use of misleading labels.

There is no such thing as “organic” salmon (or any fish) in the U.S. The Department of Agriculture (USDA) does not set specific standards for "organic" salmon, yet they are often marketed as such.¹³,¹⁴,¹⁷ These confusing labels provide false assurances to consumers.

Relying on the advice of consumer guides from the Aquaculture Stewardship Council and Seafood Watch is of limited usefulness. As a 2024 article in the Washington Post advised, “While these certifications can be a good indication that your fish is sustainable, don’t rely on them.”¹² This is because current guidelines are far from complete and could be misleading. 

For instance, the lack of a requirement for farm-of-origin labeling or farming method labeling allows consumers to unknowingly purchase salmon from producers that have a history of selling subpar salmon, even in highly regulated, “safe” countries like Norway. And “product of” labels only provide the country where the fish was last “substantially transformed,” not necessarily where it was farmed.¹²

Each certifying body also uses different standards, often focusing on specific environmental sustainability aspects while neglecting critical issues like antibiotic resistance, microplastic contamination and the use of harmful chemicals.¹⁴,¹⁵,¹⁶

The lack of clear, comprehensive labeling not only undermines consumers' ability to make informed decisions about their food but also enables producers to confuse consumers.

As a result, one 2022 study found that “many producers and retailers” have even stopped labeling salmon as “responsibly farmed” in the U.K. and only use certifications such as the ASC standard internally.¹⁹

It concluded that “unresolved environmental challenges of salmon farming, combined with perceived weaknesses in the ASC salmon standard, have led not only non-governmental organizations but also several major retailers to view the ASC as not setting the bar high enough to enable salmon farming to be defined as 'sustainable.'"¹⁹