Is wild salmon healthier than farmed salmon?

by Jennifer Bowden / 15 November, 2017
RelatedArticlesModule - Wild Salmon Farmed Healthier

Photo/Getty Images

The debate over which salmon – farmed or wild – is healthier is far from simple.

QUESTIONSome time ago, Time magazine had an article about the nutritional value of farmed versus wild salmon. The conclusion was that wild salmon was more beneficial to our health. It also discussed the fact that wild salmon have access to naturally occurring nutrients in the food chain. This has caused me to buy only sustainably fished salmon from North America.

ANSWERWild salmon was heralded as far superior to farmed salmon in Time’s 2015 article “Should I Eat Salmon?” The story quoted experts who said farmed salmon had higher levels of “saturated fat, calories, pollutants and antibiotics”. Since then, however, a Norwegian study published in the journal Environmental Research has suggested this is not always true.

Norwegian researchers collected samples of wild Atlantic salmon, caught in nets in coastal waters by commercial fisherman, and farmed Atlantic salmon, also sourced in Norway.

A standardised fillet of the wild and farmed Atlantic salmon, including its all-important fat, was then analysed for the presence of persistent organic pollutants such as dioxins (polychlorinated dibenzo-p-dioxin and dibenzofuran), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), organochlorine pesticides (OCPs) such as DDT, metals and fatty acids.

Analysis revealed that contaminant levels of dioxins, PCBs, organochlorine pesticides (DDT, dieldrin, lindane, chlordane, mirex and toxaphene) and mercury were higher in the wild salmon – though both types had levels well below the European Union’s maximum recommendations.

Concentrations of selenium, zinc, copper, iron and the omega-3 fatty acid docosahexaenoic acid (DHA) were also higher in the wild salmon.

Levels of cadmium, lead, PBDEs, and the OCPs endosulfan, pentachlorobenzene and hexachlorobenzene were low, and comparable in both wild and farmed fish. There was also no significant difference in the concentrations of the omega-3 fatty acid eicosapentaenoic acid (EPA).

Overall, there was significantly more total fat in farmed than wild salmon, because of a higher content of both saturated and monounsaturated fatty acids, as well as omega-6 fatty acids, which meant it had a higher omega-6 to omega-3 fatty acid ratio than wild salmon.

So, what does this mean in everyday terms?

Wild Atlantic salmon from off the coast of Norway contained slightly more persistent organic pollutants than farmed salmon. Persistent organic pollutants (POPs) are resistant to degradation and have the potential to affect human health.

However, wild salmon contained less saturated fat (it’s recommended that our saturated fat intake is limited to less than 10% of our energy intake) and a lower ratio of omega-6 to omega-3 fatty acid. Research suggests a lower ratio is likely to benefit our health, with evidence suggesting it suppresses the development of cardiovascular disease, cancer, and inflammatory and autoimmune diseases.

Although both types of salmon were good sources of omega-3 fats, the more beneficial fatty-acid ratio of the wild salmon potentially makes it a healthier food, even given its slightly higher persistent organic pollutant levels. But either is nutritious.

New Zealand farmed salmon is the Pacific king variety. Unfortunately, we don’t have data on levels of persistent organic pollutants in king salmon, fresh or wild. We know this salmon is a richer source of the desirable omega-3 fatty acids than Atlantic salmon. But it also contains considerably more omega-6 fatty acids.

The last National Nutrition Survey found that nearly 60% of New Zealanders were eating one or fewer servings of fish a week. That’s a shame, because fish is  low in saturated fat and an excellent source of protein, omega-3 fatty acids, iodine, selenium and many important vitamins.

So, regardless of whether it’s farmed or wild, fresh or tinned, any fish you add to your weekly diet is likely to be beneficial.

This article was first published in the September 30, 2017 issue of the New Zealand Listener.

MostReadArticlesCollectionWidget - Most Read - Used in articles
AdvertModule - Advert - M-Rec / Halfpage

Latest

How to lose weight without a diet
87141 2018-02-25 00:00:00Z Nutrition

How to lose weight without a diet

by Jennifer Bowden

"The irony is the intentional pursuit of weight loss – dieting, in other words – is actually a predictor of future weight gain."

Read more
Baby boomers are rethinking retirement for a later-life reboot
87313 2018-02-24 00:00:00Z Social issues

Baby boomers are rethinking retirement for a later…

by Sally Blundell

The biggest cohort of baby boomers is reaching retirement age – and many are not planning a quiet dotage.

Read more
School shootings and Russian indictments
87455 2018-02-24 00:00:00Z World

School shootings and Russian indictments

by Joanne Black

Slaughter in a school and Russian social-media mischief: the US is under siege.

Read more
Beck to go back to basics at Auckland City Limits
87417 2018-02-24 00:00:00Z Profiles

Beck to go back to basics at Auckland City Limits

by James Belfield

Before headlining Auckland City Limits, Beck talks about celebrating his musical past on stage and on record.

Read more
Islands of the Gulf: How the Hauraki has changed
87427 2018-02-24 00:00:00Z Television

Islands of the Gulf: How the Hauraki has changed

by Fiona Rae

A broadcaster revisits her mother’s iconic Islands of the Gulf TV series to see what’s changed since the 60s.

Read more
Hokianga's Wild West fest's unusual way of fundraising
86388 2018-02-24 00:00:00Z Life in NZ

Hokianga's Wild West fest's unusual way of fundrai…

by Peter De Graaf

Once a year, the Wild West saddles up and rides into Waimamaku for a day of highway robbery.

Read more
Back on track: $60m to go into regional rail
87519 2018-02-23 14:43:30Z Economy

Back on track: $60m to go into regional rail

by Jane Patterson

Five regions will receive just over $60 million for rebooting rail in the first chunk of money from the Provincial Growth Fund.

Read more
Ricky Houghton is about finding innovative solutions to the issues facing Māori
87510 2018-02-23 14:21:31Z Profiles

Ricky Houghton is about finding innovative solutio…

by Clare de Lore

No government on their own can fix the problems facing Māori in the Far North, warns Local Hero of the Year Ricky Houghton.

Read more