In P. G. Wodehouse's comic novels, whenever Bertie Wooster faces a particularly tricky scrape, he urges Jeeves, his brilliant valet, to eat more fish [1]. The idea that fish is brain food is older than Jeeves, and it has outlived him. Today it is a global industry built on two little molecules with unpronounceable names: EPA and DHA, the omega-3 fats.
The story of how we got here runs from a Victorian medicine spoon to the Arctic ice, a Canadian heart institute, a Nova Scotia refinery and a Prairie flax field with a science-fiction problem.
The spoonful nobody wanted
Long before omega-3 was a word, there was cod liver oil. From the 1820s, doctors in Germany noticed that young children given it did not develop rickets, the bone disease of sunless northern cities [2]. The practice spread to other countries by the 1860s, and a daily teaspoon stayed routine for children in northern Europe and the United States into the 1950s [2].
Nobody knew why it worked until 1922, when American scientist Elmer McCollum showed that a new factor in the oil, which he named vitamin D, was responsible [2]. Generations of children who held their noses for that spoonful were, it turns out, taking a vitamin supplement before vitamins had names.
1970s: the Greenland hypothesis
The omega-3 boom began on the ice. In the 1970s, two Danish physicians, H. O. Bang and J. Dyerberg, studied the Inuit of Greenland, whose traditional diet was rich in fish, seal and whale [3]. They reported that heart disease seemed rare among them, and they credited the marine fats in their food [3].
It was a powerful story: a traditional Arctic diet that appeared to protect the heart. It helped launch fish oil capsules as a global billion-dollar business [3].
2014: a Canadian cardiologist checks the receipts
Forty years later, a team led by Dr. George Fodor, then of the University of Ottawa Heart Institute, went back to the original work. Writing in the Canadian Journal of Cardiology in 2014, they found that Bang and Dyerberg had never actually measured how common heart disease was. They had relied on public health records and hearsay [3]. Other studies suggested the Inuit had heart disease at rates similar to other populations, and very high stroke death rates [3].
That does not mean omega-3s do nothing. DHA is a major building block of the brain and eyes, which is why it is added to infant formula and prenatal supplements. It does mean that a famous "fact" behind the fish oil aisle was more hypothesis than proof, and that buyers should treat bold claims carefully.
Canada's omega-3 supply chain
Canada sits on both main sources of omega-3.
From the sea. In Nova Scotia, Ocean Nutrition Canada grew from a four-person start-up in 1997 into a major omega-3 producer, refining fish oil at Mulgrave and making microencapsulated powders that let food companies add omega-3 to bread, juice and yogurt without a fishy taste [4]. In 2012, the Dutch company DSM bought it for C$540 million [4]. Fishery leftovers, not just whole fish, feed this chain, which is exactly the kind of value addition that turns a by-product into a premium ingredient.
From the land. Canada is one of the world's largest producers and exporters of flaxseed, a rich plant source of ALA, the plant form of omega-3 [5]. In 2025 Canada grew 454,461 tonnes of flax and exported C$229.7 million worth [5].
And here is the science-fiction twist. In 2009, traces of an unauthorised genetically modified flax called CDC Triffid turned up in a shipment bound for Europe. It shares its name with the walking killer plants of John Wyndham's 1951 novel The Day of the Triffids. Exports to the EU stopped, and when trade resumed every shipment had to be sampled and tested [5]. Canada asked for the requirement to end in 2024, and the EU has now agreed, removing a cost that had put Canadian exporters at a disadvantage for more than 15 years [5]. A single unauthorised variety cost an industry years of paperwork.
What it means for buyers
- Know your omega-3. Fish and algae oils supply EPA and DHA. Flax supplies ALA, which the body converts poorly. Labels and prices should reflect the difference.
- Check the claims. In Canada, omega-3 supplements are natural health products that need a Health Canada licence and an NPN on the label [6]. Be wary of products that promise more than the evidence supports [3].
- Look at by-products. Fishery and processing leftovers are a growing source of high-value oils and ingredients.
- Watch the paperwork. As the Triffid story shows, one compliance failure can shut a market for years. Traceability is cheaper than recovery [5].
Jeeves was half right
Fish will not make anyone as clever as Jeeves, and the Greenland story was weaker than the industry claimed. But omega-3 remains one of the most important nutrients in modern food, and Canada, from Nova Scotia's refineries to Saskatchewan's flax fields, is well placed to supply it.
Nature Shire helps Canadian food, seafood and wellness brands reach buyers worldwide. Follow us on X at @NatureShire for more stories from the food system.
References
- McGill University Office for Science and Society, Is fish really brain food? (20 March 2017).
- Wikipedia, Cod liver oil.
- CBC News, Popular fish oil study "deeply flawed," new research says (2014), on Fodor et al., Canadian Journal of Cardiology.
- Wikipedia, Ocean Nutrition Canada.
- World Grain, Non-tariff barrier ending for Canadian flaxseed exports to EU (2026).
- Health Canada, Natural health product licensing.
