Omega-3 is one of our favourite supplements but a huge new survey has received it has little or no benefit. How did it become a $30 bn business?
The omega-3 industry is in a twisting. Again. Last week, Cochrane, an organisation that compiles and assesses medical research for the 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 change to danger of cardiovascular events, coronary heart demises, coronary heart disease events, stroke or heart irregularities “.
I can’t say that I was especially surprised. Over the past 15 years, more than 20 surveys have shown a similar absence of effect. But what does surprise me is how we continue to look at the world of fish and seafood through the amber lens of a fish petroleum 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.
The confusion develops in part from the historical luggage of fish oil and the $30 bn( PS23bn) 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 aimed up bowlegged by adolescence. Researchers eventually pieced the puzzle together and concluded that the disease is a result of 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 sums within the liver of codfish.
A Norwegian pharmacist named Peter Moller confiscated 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 squad then launched a campaign to institutionalise the regular employ of cod-liver petroleum, 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 petroleum steam mills to his name, churning out 5,000 barrels of the stuff a year. By the time omega-3s started to be a focus of medical research, there was already a rosy impression around fish oil.
In the early 1970 s, the chemist Hans Olaf Bang read in a Danish periodical 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 laboratory in Copenhagen recently. They estimated that in 20 years, the traditional Inuit diet would have changed to the western diet, and Dyerberg recollects 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 examine “. In an association analyse, 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: 1) 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. 2) Inuit people also had, according to public health records, markedly lower rates of coronary heart disease. They hypothesised that therefore 3) omega-3s might reduce the risk of coronary heart disease.
This was backed up by further laboratory analyses that did demonstrate, 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 proving causation. That is where this latest round of studies comes in.
The Cochrane study and the others that preceded it have one thing in common: they are meta-analyses of” randomised control trials”( RCTs ). That is, trials where patients are given a supplement at random and tracked over time against another set of patients given a placebo. Most statisticians consider these trials to be the very top of the evidence pyramid. But it is these studies that have at times proven troublesome for Omega World. Each day RCTs come to illuminated that display little or no effect, Omega World tends to blend its counterargument with proof from association surveys because, as a recent industry reply to the Cochrane report put it,” it’s all connected “.
When it then turns to the RCTs, the industry, as would be expected, looks for different explanations as to why positive health outcomes weren’t reported. In the explosion of RCTs preceding Cochrane, the Omega World line was that these most recent trials did not show benefits because things such as statins, stents and other forms of cardiovascular intervention masked the anti-inflammatory effect of fish petroleum pills; earlier RCTs had shown a fairly significant effect, but none of those treatments existed at the time of those trials.
The industry also, and I believe rightly, pointed out that surveys often failed to look at omega-3 blood lipid levels before and after supplementation. In other terms, it’s not really a fair trial if you don’t know where the patients started with respect to the omega-3 levels in their blood. If we only measure impact without looking at omega-3 levels in the blood at the outset, aren’t we doing the dietary equivalent of testing how far a auto can drive without checking how much petrol is in the tank at the start?
With Cochrane, the latest industry debate is that the study’s authors cut out a number of different forms of cardiac ailments, thus skewing the stats. In particular, it notes that Cochrane failed to include” sudden cardiac death” and” sudden cardiac mortality” in its listing of outcomes. Since almost half of all patients first report heart disease to their doctors by abruptly falling dead, this is not an insignificant exclusion.
But the fact that the industry’s debates shift with each new, damning meta-analysis gives you intermission. What is going on? Is there an international conspiracy to discredit omega-3s? Or does Omega World keep moving the goalposts? When I posed this question to 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, she made it seem as if the problem didn’t even exist.” As a matter of fact, we track media sentiment … and have found many more positive omega-3 tales than negative, in general. Of course, the negative stories are the ones that catch people’s attention. As we both know, negative tales are much more interesting and the media is definitely guilty of sensationalist’ clickbait’ headlines such as:’ Omega-3s don’t work .'”
As sympathetic as I am to the trials of Omega World, as analyzes continue to poke holes in aspects of the omega-3 cardiovascular argument, I can’t help supposing there is something else going on. Because, while the fish petroleum supplement business is a big deal, it is also a sheen on the surface of a much deeper pond. Long before omega-3 supplements became popular, an industry developed that used the same omega-3-rich animals not for medication, 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 devours millions of tonnes of marine wildlife every year. Today, one in every four kilograms of fish capture is reduced into oil and snack and used for agriculture, land animal husbandry and, most recently, fish farming, AKA aquaculture.
The reduction industry has appeared in different forms under different ownership over centuries of human history. In the 18 th century, it targeted whales, reducing northern hemisphere cetacean populations into isolated pockets of endangered species in order to attain lamp oil and lubricants. In the 19 th and early 20 th centuries, it shifted to the southern hemisphere, reducing 390,000 of the 400,000 great whales that once wandered the Southern Ocean to margarine, nitroglycerine and other ” marine ingredients “.
In the latter half of the 20 th century, it changed again and targeted small, oily fish such as anchovies, sardines and herring. In the late 1940 s and early 1950 s, the largest reduction operation in human history started off the shores of the Peru in pursuit of the Peruvian anchoveta. The Peruvian anchoveta is by far the largest single species catch by tonnage in the world, some years comprising as much as 10% of all fish caught. And although Peruvian anchoveta are as delicious as any anchovy on Earth, an industry-influenced Peruvian statute dictates that more than 95% of the catch must go to the reduction industry.
Each decade brings a different used only for all those anchovies. In the 1940 s, they were used for fertiliser. In the 50 s and 60 s, chicken feed. In the 70 s, pet food and pig feed. In the 80 s and 90 s, aquafeed for salmon and other carnivorous fish. And now, the most upper-class product of the reduction industry: dietary supplements.
And it is not just Peruvian anchoveta that are reduced into fish dinner and oil. All told, the reduction industry removes from the ocean 20 m-2 5m tonnes annually- the equivalent of the combined weight of the population of the United States. The omega-3 industry argues that some vendors are turning to much more sustainable alternatives, such as algae-based omega-3s and fish petroleum reclaimed from recycled byproducts.
Nevertheless, the reduction industry processions on into new territory. Most recently, it has begun targeting Antarctic krill, the keystone prey species of the entire Antarctic ecosystem. Two years ago, when I asked the then chief executive of the largest krill extractor in the world why it had launched a $200 m fishing operation in the Southern Ocean to take food out of the mouths of whales, he noted that krill oil is a “phospholipid” and building it much more “bioavailable” means that consumers can take a much smaller pill. Why was this important? Customers who chose krill oil over fish petroleum would be much less likely to suffer the horrors of a fishy burp.
Amid all the conflicting reports, there is one bit of data that glistens out: 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: 100 g of salmon contains 139 calories and 23 g of protein. By comparing, 100 g of beef contains 210 calories and 20 g of protein.
Harvesting wild fish from well-managed stocks requires a fraction of the carbon as farming terrestrial livestock. Similarly, fish agriculture puts a lesser burden on the Earth in terms of carbon and freshwater use than pretty much any form of terrestrial animal husbandry. We could attain the farming of fish even more carbon- and resource-efficient if we used alternative ingredients for fish food based on algae and food waste. And if you consider growing” filter feeders” such as mussels, clams and oysters, the benefits are even more extreme. These bivalves don’t have to be fed anything, and make water cleaner even as they grow fatter. They provide protein 30 times more efficiently than cattle.
Is the epidemiological proof 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 person 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 analyses. And, while one such analyze associated feeing 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 feeing fish.
But what we do know is this: 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 merely puts pills in our cupboards. Is this the way we want to continue to do business with the planet?
Paul Greenberg is the author of The Omega Principle: Seafood and the Quest for a Long Life and a Healthier Planet ( Penguin Press ).
* The subheading of this article was revised on 25 July 2018 to clarify that it was for heart health or strokes that the study observed omega-3 had little or no benefit.
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