Is Farmed Salmon ‘The Most Toxic Food in the World’?

Check out this answer from Consensus:

Farmed salmon does contain some toxins, but the levels are generally lower than those found in wild salmon and are often within safe limits. Continuous monitoring and improvements in aquaculture practices have contributed to the reduction of contaminants in farmed salmon, making it a safer and nutritious option for consumers.

The consumption of farmed salmon has been on the rise globally due to its nutritional benefits and the increasing demand for seafood. However, concerns about the presence of toxins in farmed salmon have been a topic of debate. This article explores whether farmed salmon contains any toxins, drawing on findings from multiple research studies.

Persistent Organic Pollutants (POPs)

Persistent Organic Pollutants (POPs) such as dioxins, polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) are a significant concern in seafood safety. Studies have shown that farmed salmon generally contains lower levels of these contaminants compared to wild salmon. For instance, a comprehensive study found that wild Atlantic salmon had higher levels of dioxins, PCBs, and OCPs than farmed salmon1. Another study monitoring Norwegian farmed salmon over a 13-year period reported a decrease in the levels of dioxins and dioxin-like PCBs, making the consumption of farmed salmon safer over time2.

Heavy Metals

Heavy metals such as mercury, cadmium, and lead are also monitored in farmed salmon. Research indicates that the levels of these metals in farmed salmon are generally low and often below the legal limits. For example, a study on Norwegian farmed salmon found that the levels of mercury and other heavy metals had decreased over the years, ensuring that the fish were safe for consumption2. Similarly, another study comparing farmed and wild Atlantic Bluefin tuna found that farmed tuna had lower mercury levels, making it a safer option7.

Other Contaminants

Farmed salmon can also be exposed to other contaminants such as cyanobacterial toxins and botulinum toxin. A study analyzing shrimp and farmed fish in Canada found no detectable levels of cyanobacterial toxins in the samples tested6. However, concerns about botulinum toxin production in packaged salmon under certain conditions have been raised. Research suggests that the use of semipermeable packaging films can mitigate the risk of toxin production, ensuring the safety of the fish5.

Nutritional Considerations

While farmed salmon may contain some contaminants, it is also a rich source of essential nutrients such as omega-3 fatty acids. Studies have shown that farmed salmon contains higher levels of omega-6 fatty acids but comparable levels of eicosapentaenoic acid (EPA) and lower levels of docosahexaenoic acid (DHA) compared to wild salmon1. Despite the lower DHA levels, farmed salmon still provides significant nutritional benefits, contributing to the recommended intake of omega-3 fatty acids8

Is farmed salmon ‘the most toxic food in the world’?

L Neil Frazer has answered Unlikely

An expert from University of Hawaii at Manoa in Earth Sciences, Marine Biology

Farmed salmon isn’t toxic to the people who eat it, but it is certainly “toxic” to the juvenile wild salmon who must pass salmon farms during their out-migration from their natal streams to the ocean . The sea lice and viruses from the salmon farms can be devastating to wild salmon populations.

Nearly all salmon farming is conducted in sea-cages, which protect the farmed salmon from large predators such as seals and porpoises. However, sea-cages do not exclude pathogens and parasites, which pass freely through the mesh of the cage. Being protected from predators, and fed every day, farmed salmon can live for a long time after becoming diseased. During this time they are constantly shedding pathogen into the water, and the elevated levels of pathogen cause wild fish populations to decline. A salmon farm is thus an unintentional pathogen culture facility.

There is yet another sense in which farmed salmon is “toxic”, which is that little oily fish needed to manufacture feed for farmed salmon are an important source of protein in the diets of third world countries. The oil from these fish is needed for salmon feed because salmon are carnivores: even farm salmon cannot thrive without fish oil in their diets. In consequence, the growing of one pound of farm salmon requires the removal of three to five pounds of wild fish from the ocean.

Is farmed salmon ‘the most toxic food in the world’?

Peter D Nichols has answered Extremely Unlikely

An expert from Commonwealth Scientific and Industrial Research Organisation in Analytical Chemistry, Marine Science, Nutrition

CSIRO has performed independent analyses of farmed Tasmanian Atlantic salmon, including with emphasis on the health-benefiting long-chain omega-3 oils. Farmed Tasmanian Atlantic salmon is actually one of the best sources available for Australian consumers of these ‘good oils’. Increasing emphasis also has been placed by the Australian producers on the use of sustainable diets. The diet for this important farmed species now includes use of plant and animal derived ingredients, all produced sustainably and using best practices. Other new CSIRO research has seen further development of land plant sources of the long-chain omega-3 oils, and use of these new sources will allow in the future the content of these ‘good oils’ to increase again.

Is farmed salmon ‘the most toxic food in the world’?

Aleksei Krasnov has answered Extremely Unlikely

An expert from The Norwegian Institute of Aquaculture in Fisheries Sciences

Salmon feeds are made from high quality ingredients that are also used for human consumption. Vaccination success has reduced the use of antibiotics. Farmed salmon is safer than wild fish that can be exposed to environmental pollution.

Is farmed salmon ‘the most toxic food in the world’?

Mo D Salman has answered Unlikely

An expert from Colorado State University in Epidemiology, Veterinary Science

The use of the term “toxic” is wrongly used for an approach to expand on the production of efficient protein to feed the expanded growth of human population. The extensive aquatic farming including farmed salmon, however, has some negative impact on our biological security if this practice is left without consideration to the environment and biological factors that the practice should adjust for.

Is farmed salmon ‘the most toxic food in the world’?

Rafael Franco has answered Extremely Unlikely

An expert from Universitat de Barcelona in Parkinson’s Disease, Alzheimer’s Disease, Antioxidants, Nutrition, Pharmacology, Asthma, Cell Biology, Biochemistry

No. I checked the link: “that is the most toxic food in the world” and info there not scientifically sound.

One may wonder about the approppriate number of fish farms and the best proportion of farms of this versus those of such fish, but farmed salmon cannot be the most toxicc food in the world. Better wild salmon? obvious, as in any other case of “wild versus farmed fish”.