The Omega-3 industry is in a twist. Again.
Recently, Cochrane, an organisation that compiles and evaluates medical research for the general public, released a meta-analysis — a study of studies — to determine whether or not omega-3 pills, one of the world’s most popular dietary supplements, reduced the risk of coronary heart disease.
After comparing 79 trials involving 112,059 people, the researchers could find “little or no difference to risk of cardiovascular events, coronary heart deaths, coronary heart disease events, stroke or heart irregularities”.
Over the past 15 years, more than 20 studies have shown a similar lack of effect.
But what is surprising is how we continue to look at the world of fish and seafood through the amber lens of a fish oil capsule.
Omega-3s do something in our bodies — and probably something important.
But without the larger context of the marine organisms that contain them, omega-3s get lost in the noise of human metabolism and modern marketing.
It was do with rickets, to begin with
The confusion arises in part from the historical baggage of fish oil and the $30 billion industry associated with omega-3 extraction. Once upon a time, fish oil solved a major human health problem. But it had nothing to do with coronary heart disease. During the Industrial Revolution, a disease became increasingly prevalent throughout northern Europe: rickets. Malnourished children in sunlight-poor urban slums often ended up bowlegged by adolescence. Researchers eventually pieced the puzzle together and concluded that the disease was caused by a deficiency in vitamin D, which the body naturally generates in the presence of sunlight. And, as it turned out, vitamin D is stored in high amounts within the liver of codfish.
barrels a year of cod liver oil were being produced in the 19th century by Peter Moller, a Norwegian pharmacist, who promoted its use
A Norwegian pharmacist named Peter Moller seized upon this finding (and many other anecdotal stories about the curative properties of cod-liver oil).
Using a patented chemical process, he arrived at a product that, he announced to the world, “didn’t taste fishy”.
Moller and his advertising team then launched a campaign to institutionalise the regular use of cod-liver oil, regardless of whether you were at risk of rickets or not.
The campaign was a success: a spoonful a day became common practice. Moller built his company into an international presence and died in 1869 with 70 cod-liver oil steam factories to his name, churning out 5,000 barrels of the stuff a year.
And then came the study on Inuits
In the early 1970s, the chemist Hans Olaf Bang read in a Danish journal that there were extremely low incidences of cardiovascular disease in Inuit communities of Greenland.
He and his assistant, Jorn Dyerberg, travelled to Uummannaq on the north-west coast of Greenland to investigate.
At the time of the expedition, Bang didn’t quite know what he wanted to test for. They probed and palpated 130 local people, measured height and weight, and came home with a lot of blood.
“We had these 130 precious samples of blood,” Dyerberg told me in his lab in Copenhagen recently.
They estimated that in 20 years, the traditional Inuit diet would have changed to the western diet, and Dyerberg remembers Bang saying: “’There will never be anyone who can do this again, so let’s do whatever we can!’ And we decided to do fatty acid analysis.”
The result of their analysis was a hypothesis that is an exemplary “association study”.
In an association study, multiple factors are logged and a hypothesis of correlation is drawn from the findings.
In the case of the Bang and Dyerberg Inuit study, they found that:
■ Inuit people in Greenland had a diet high in omega-3 fatty acids and blood lipid levels of omega-3s much higher than their western contemporaries.
■ Inuit people also had, according to public health records, markedly lower rates of coronary heart disease. They hypothesised that therefore...
■ omega-3s might reduce the risk of coronary heart disease.
This was backed up by further laboratory studies that did show, in vitro, that omega-3s were involved in anti-inflammatory reactions.
But — and this is a big but — while correlations abound for omega-3s and heart disease, the real trouble has always been in showing causation.
That is where this latest round of studies by Cochrane comes in.
Ellen Schutt, the executive director of the Global Organization for EPA and DHA Omega-3s, probably the world’s most prominent omega-3 advocacy organisation, said: “As a matter of fact, we track media sentiment ... and have found many more positive omega-3 stories than negative, in general.
Of course, the negative stories are the ones that catch people’s attention.
As we both know, negative stories are much more interesting and the media is definitely guilty of sensationalist ‘clickbait’ headlines such as: ‘Omega-3s don’t work.’”
As we both know, negative stories are much more interesting and the media is definitely guilty of sensationalist ‘clickbait’ headlines such as: ‘Omega-3s don’t work’.”
- Ellen Schutt | Executive director, Global Organisation for EPA and DHA Omega-3s
Birth of the reduction industry
Long before omega-3 supplements became popular, an industry arose that used the same omega-3-rich creatures not for medicine, but for an odd array of agricultural and industrial purposes.
Ultimately, it was this so-called “reduction industry” that created the oily-fish extraction system that now consumes millions of tonnes of marine wildlife every year. Today, one in every 4kg of fish caught is reduced into oil and meal and used for agriculture, land animal husbandry and, most recently, fish farming, or aquaculture.
Researchers eventually pieced the puzzle together and concluded that the disease was caused by a deficiency in vitamin D, which the body naturally generates in the presence of sunlight. And, as it turned out, vitamin D is stored in high amounts within the liver of codfish.
And now, the most elite product of the reduction industry: Dietary supplements.
All told, the reduction industry removes from the ocean 20 million to 25 million tonnes annually — the equivalent of the combined weight of the population of the US.
The omega-3 industry argues that some vendors are turning to much more sustainable options, such as algae-based omega-3s and fish oil reclaimed from recycled byproducts.
Nevertheless, the reduction industry marches on into new territory. Most recently, it has begun targeting Antarctic krill, the keystone prey species of the entire Antarctic ecosystem.
The omega-3 industry and the reduction industry that bred it removes fish from the water in a way that doesn’t put protein on our plates — it just puts pills in our cupboards. Is this the way we want to continue to do business with the planet?
Is there any truth to Omega- 6 claims?
Amid all the conflicting reports, there is one bit of data that shines out: eating fish and seafood can bring considerable health and environmental benefits. Fish, in addition to providing us with omega-3s, delivers protein with far fewer calories than meat.
100g of salmon equals 139 calories and 23g of protein.
100g of beef provides 210 calories and 20g of protein.
Is the epidemiological evidence for fish-eating better than simply taking a fish oil pill? Again, we are stuck with the problem of correlation versus causation. It is very difficult to feed someone a fish in such a manner that they don’t know they are eating a fish. Hence an RCT of seafood-eating hasn’t really ever been done. Most of the studies around seafood are association studies. And, while one such study associated eating fish twice a week with a possible reduction in mortality of 55,000 lives a year, we don’t know what a fish-eater does with the rest of their life beyond eating fish.
— Paul Greenberg is the author of The Omega Principle: Seafood and the Quest for a Long Life and a Healthier Planet (Penguin Press).