In recent weeks, a number of companies have increased their commitment to sustainably-sourced fish. However, at the same time fish supplies are under increasing pressure as consumers are urged to eat more fish for health reasons. Ben Cooper reports on how a desirable public health objective has come into conflict with a sustainability goal.

Over the past few weeks, a number of companies have trumpeted their commitment to sustainable fish, and it is not hard to see why. Environmental awareness about overfishing and concern over the environmental impacts of fish farming has been growing steadily, and as food producers and retailers seek to be greener, it is an issue that shouts for attention.

But another reason why sourcing fish sustainably has become such a key issue comes down to the simple fact that consumers are eating more fish as part of the general move towards healthier eating, and in particular in response to the much vaunted benefits of omega-3 fats. With public health advocates urging people to eat more fish, this appears to be a situation where a socially desirable outcome is at odds with an environmental one.

The American Diabetes Association and the American Heart Association recommend eating fish twice a week, with research suggesting this can reduce the risk of dying from heart disease by a third. Eating more fish can also reduce susceptibility to stroke, depression and Alzheimer’s. Fish are a healthy source of protein and many species are high in vitamin D, while fish are also a source of the trace mineral, selenium, the antioxidant properties of which can help prevent cellular damage from free radicals.

But it is the omega-3 fats, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), in oily fish that have received so much publicity in recent years. In the UK, the Food Standards Agency (FSA) also recommends people eat two portions of fish a week, and specifically states one portion should be oily fish. 

DHA has been shown to play an important role in brain and visual development in infants, and is now included in many brands of infant formula. Meanwhile, DHA and EPA both boost heart health in adults, lowering triglycerides and blood pressure and easing inflammatory processes.

Some research has been published dissenting from these generally held views. Some studies have suggested eating large amounts of fatty fish may exacerbate conditions of people with serious heart conditions, while there is concern over the fact that general fish stocks are high in other contaminants, such as mercury. But the overall tenor of public health information on fish is overwhelmingly positive. 

The average adult weekly intake in the UK is thought to be about 1.5 portions, one third of which is oily fish, and Greenpeace is concerned about the environmental impact of the FSA target intake levels being reached. “Fish stocks are in crisis globally and any advice related to eating fish needs to take that into account,” says a spokesperson for Greenpeace UK. 

According to Greenpeace, if the FSA’s suggested intake levels were met, the present total level of fish consumption in the UK would need to increase by over 40%, with oily fish consumption increasing by over 200%. The UN’s Food and Agricultural Organisation (FAO), meanwhile, forecasts that per capita fish consumption in Europe will rise from 22kg in 1998 to 24kg by 2030.

The FSA said last year it would be reviewing its guidance in respect of environmentalists’ concerns. However, an FSA spokesperson has confirmed to just-food that it will not be altering its intake guidance, but is looking to add a message relating to sustainability, urging consumers to think about where their fish comes from and directing them to other information sources on sustainability such as the Department for Environment, Food and Rural Affairs (DEFRA) and The Marine Stewardship Council. “We won’t be changing the recommendation that people need to eat two portions a week, one of which should be oily,” the spokesperson said. “It’s just that we will be providing more information to help people make a more sustainable choice.”

Opinion research suggests public education on the health benefits is registering more strongly with consumers than messages about endangered fish supplies. A poll of 2,000 adults by market UK researcher YouGov showed that 72% were unaware that some fish are nearing extinction, while 78% said they did not attempt to buy sustainably-sourced seafood. Research conducted by the Sea Fish Industry Authority (SFIA) showed that only 10% of consumers think about sustainable, ethical or environmental concerns every time they buy seafood, while 42% think about these issues sometimes.

On the other hand, another piece of research by SFIA found awareness of the benefits and sources of omega-3 to be “very high”. At least 50% of study participants were either found to be taking, or giving to their children, an omega-3 supplement or buying food fortified with omega-3. 

Of course, not all fish are in peril. According to the US-based Environmental Defense Fund, environmentally friendly fish include Atlantic mackerel, char, pollock, and wild salmon. However, it urges consumers to avoid farmed salmon and trout, both of which are high in omega-3s, because of the large amounts of smaller oily fish it takes to feed them. Frustratingly, farmed catfish is seen as one of the most benign fish products from an environmental standpoint but has very low levels of omega-3s. 

The logical move to reconcile the conflicting aims of boosting omega-3 consumption and protecting fish stocks is to find alternative sources of the same fatty acids, though this is easier said than done. There is a fat found in plants called alpha-linolenic acid (ALA), which our bodies can convert into EPA and DHA. This is why flaxseed and walnuts are often marketed as being a source of omega-3s.

While research has shown an ALA-rich diet to be good for heart health, the conversion from ALA to omega-3s is not particularly efficient, with little DHA produced, so ALA will not necessarily meet the desired DHA requirements. Omega-3s can also be found in algae. In fact, much of the DHA used in infant formula is produced from algae. However, algae-based DHA capsules are more expensive to produce.

The issue may be seen by some as a trade-off between personal and planetary health. However, while market research suggests consumers are less interested in sustainable fish supplies than in the positive health benefits of eating fish, it also suggests there is still considerable ignorance about the former.

Moves of the kind seen recently by UK grocer Waitrose, Pret a Manger and Canadian retailer Loblaw may help to redress the balance.