Scanning the shelves and the internet for fish oil is a dizzying task. There are dozens of brands available and although the typical consideration for the popular supplement is that quality matters most, it is not the only factor.
These prized products go a long way before being labeled as “pure” and “fresh” – starting with the industrial-scale milling of a small fish that is crucial to the health of oceans and food systems.
While some fish oils are made from cod, mackerel, or sardines, most come from Peruvian anchovies, a type of anchovy. These silvery fish are an important source of nutrition for the fauna of the Humboldt Current, one of the most productive marine ecosystems on the planet.
“I think people should know where the fish in their fish oil comes from. It’s always good to have a face on the product they’re consuming,” says Katrina Nakamura, founder of the Sustainability Incubator, which examines working conditions in food supply chains.
As the largest fishery in the world, anchovy catches in Peru are enormous – exceeding 4 million tonnes per year. Some of the transport is frozen and canned for human consumption, but it is mainly used to feed pigs, poultry and farmed fish.
Aquaculture is a growing global industry, valued at over £146 billion in 2020, with China topping the list as the biggest fish-producing country, producing 58.8 million tonnes a year. Aquaculture now provides half of all seafood consumed by humans – a figure that is expected to rise to 62% by 2030.
Today, major industry players in Peru also want to expand fish oil operations for dietary supplements.
Although there is still debate among scientists about the benefits of golden supplements, there is evidence that omega-3 fatty acids, including EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), may help to heart and brain function, reduce the risk of cognitive impairment and may help reduce inflammation.
Anchovies are rich in EPA and DHA. According to the World Organization for Omega-3 EPA and DHA (GOED), the industry body for omega-3 producers, an estimated 38,000 tons of anchovy oil are extracted for dietary supplements each year.
“It’s mind-boggling. What we can catch in a week is what many countries catch in more than a year,” says Patricia Majluf, vice president of Oceana Peru, which is part of the international conservation organization that campaigns to protect and restore the world’s oceans. “And the processing capacity of the factories is even greater.”
Although highly regulated, the fishery has recently been condemned for misreporting catches and for putting workers’ health at risk throughout the Covid-19 pandemic by failing to isolate crew members. infected, resulting in large outbreaks, according to a report by Changing Markets. Foundation, which investigated in 2020 harmful and unsustainable practices in the Peruvian fishmeal and fish oil industry.
The fishery would also catch too many juvenile anchovies – if the fish are caught before they spawn, the population cannot sustain itself. Oceana reported that some factories in southern Peru are operating illegally without proper permits or licenses and producing fishmeal under unsanitary conditions, while distorting catch quotas.
Although Peruvian anchovies are in danger of being overexploited, and the fishery was on the verge of collapse in the early 1970s, the companies responsible face few penalties. The regulations impose temporary closures in areas where catches of juveniles exceed 10%, but seven major companies in the sector flouted this rule between 2016 and 2019 and continued to operate in areas already identified as having a surplus of juveniles. In one case, 80 fishermen were threatened with dismissal for refusing to fish for juveniles.

“We extract millions of tonnes from an ecosystem that depends on this fish. The ecosystem becomes impoverished and loses its resilience in the face of the great changes caused by El Niños and climate change,” says Majluf.
“This fish could be used to feed our people. An industry that pays almost nothing for this fish takes everything away.
Major brands of fish oil, including Nature’s Bounty, natural, Sleep and Kirkland promote their products as sustainably sourced from Peru; some mention anchovies as an ingredient. For example, Nature’s Bounty states, “We go to Peru because the Peruvian government has strict standards and governance over the surrounding waterways, to properly ensure the protection of the fish…all catches in Peru are carefully vetted to meet rigorous quality controls.
But what ends up on the shelves may still be a rotten lot: Independent tests show that an alarming amount of fish oil supplements, at least 10%, are rancid. Some products reached 11 times the international voluntary rancidity limits.
“It’s quite a long road for fish oils to get to you,” says Dr. Ben Albert, a researcher at the University of Auckland and a researcher on the health effects of oils. “[Rancidity] it is unlikely to come from caught fish.
Oxidation is a normal and usually harmless process, but rancidity occurs when a product is heavily oxidized. In fish oil, this happens when the oil is exposed to light, air or heat, which tends to happen in the long and complex supply chain involved in refining the raw product.
Trade data is limited, but what is available shows that ships can pick up a cargo of crude fish oil in Peru and ship it to China for extraction and distillation. From there, the oil is transported to North America or Europe to be packaged there. It is difficult to protect the product throughout the production process. Time spent outdoors or in warm conditions increases the likelihood of oxidation.
“That’s part of the problem: we don’t know who these companies are exporting to. There are so many chains along the way,” says Alfonso Daniels, researcher on the Changing Markets report.
In general, fish oil supplements are hard to trust, says Albert. Although this should not be left to the consumer, his recommendation is to buy smaller quantities and store fish oils in darker, cooler places to avoid further oxidation.
None of the Peruvian companies or authorities responded to the Guardian’s request for comment.
Alternatives such as krill or algal oil also contain unsaturated fats which allow oxidation to occur. Although both products are generally marketed as a more “environmentally viable” option for overfishing critical fish populations, concerns remain that krill are often caught using harmful fishing practices, and further research is needed. to develop efficient production from algae.
During this time, fish oil continues to be the supplement of choice. “I think fish oil is a good product. I’m not mad at the fish oil industry for existing. But they have to respect the people in the supply chain, and they have to respect the fish and the ecosystem where the fish comes from,” says Nakamura.