Swim against the tide

Associated with an abundance of cultures, religions, holidays and regions the world over, fish and seafood have been part of daily life arguably since human life began. Fish are used as symbols, dishes associated with festivities and as part of a day-to-day diet for many. The Ocean Conservatory estimates that as much as 40% of the world’s population, around three billion people, rely on fish as their main source of protein: from the Arctic to the Caribbean, and the Middle East to Asia. Even in the US, fish and seafood play a vital role in diets. Often, local traditions define how and when they are consumed, making them regional delicacies.

However, concern is growing over how much seafood we consume or even have access to. According to the Harvard School of Public Health, just one in five people in the US understand the true benefits of this highly nutritious food source. This equates to just one-third of people in the US eating seafood once a week, and not even half eating fish just occasionally, if at all.

“There are many reasons why people aren’t meeting dietary recommendations for seafood,” says Ellen Schutt, executive director of GOED. “Other protein sources can be less expensive, people aren’t as confident in their ability to prepare it well, and some just don’t like the smell or taste of fish.”

Concurring with that view, the Harvard School of Public Heath has also said others may avoid seafood because of concerns around mercury, pesticide residues or other possible toxins believed to be associated with some types of fish and the harm they may do to them or their children. This is despite the fact that fish and their associated benefits are essential to human development, particularly during pregnancy and formative years. Fish and other seafood are known to be a vital source of the long-chain omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

The science behind the substance

According to the WHO, DHA is a major building block of the body’s neural system, vitally important for optimal brain and neurodevelopment in children. In an analysis piece written by Jogeir Toppe of the UN’s Food and Agriculture Organisation (FAO) and published by the WHO, it said an FAO/WHO expert consultation concluded that fish lowers the risk of women giving birth to children with suboptimal development of the brain and neural systems compared with women not eating fish.

Toppe wrote: “Alternative sources of omega-3 fatty acids are found in many vegetable oils, but this is mainly alpha-linolenic acid (ALA) that needs to be converted into DHA. However, in our bodies, the conversion from ALA into EPA and DHA is in many cases inefficient, making it difficult to rely only on vegetable oil during the most critical periods of our lives, namely during pregnancy and the first two years of life (the 1,000-day window).” Schutt agrees, adding: “Research suggests that pregnant mums with higher EPA and DHA levels have a significantly reduced risk for early preterm birth.”

However, it is not just during pregnancy and the first few years of life that fish or certain other kinds of seafood can play a vital role in a healthy lifestyle. Astaxanthin and other healthy chemicals the human body does not produce can be found in fish; for example, to maintain a healthy heart and brain it is vital to consume food high in omega-3 fatty acid. Astaxanthin is also an anti-oxidant, which can help with issues such as cancer, skin health, mental health and cardiovascular health.

According to the Harvard School of Public Health, some of the known benefits include helping to maintain a healthy heart by lowering blood pressure and reducing the risk factors for cardiac events such as sudden death, heart attack, abnormal heart rhythms and strokes; aiding healthy brain function and infant development of vision and nerves during pregnancy; the reduction of depression risk factors, ADHD, Alzheimer’s disease, dementia, and diabetes; and to prevent inflammation factors and reduce the risk of arthritis.

“In the omega-3 space, it’s also important that people choose certain types of fish and seafood that are better sources of EPA and DHA omega-3s,” says Schutt. Such products can include salmon, trout, sardines, herring, canned mackerel, canned light tuna and oysters. “People need to remember that good omega-3 rich seafood isn’t just found in restaurants or in the seafood case. There are great options in the frozen and canned food aisle that will give people the nutrition they need,” she adds.

However, it is important to acknowledge the concerns people have. The Harvard School of Public Health does so, noting research into the field. A post on Harvard’s TH Chan’s Nutrition Source entitled ‘Fish: Food or Foe?’ concurs that the contaminants of most concern when it comes to fish are mercury, polychlorinated biphenyls (PCBs), dioxins and pesticide residues. “Very high levels of mercury can damage nerves in adults and disrupt development of the brain and nervous system in a foetus or young child. The effect of the far lower levels of mercury currently found in fish are controversial. They have been linked to subtle changes in nervous system development and a possible increased risk of cardiovascular disease,” the post says.

However, it adds that a comprehensive report by the Institute of Medicine, looking at the risks-benefits question of eating fish, concluded the risk of cancer from PCBs was “overrated”. “Numerous pollutants make their way into the foods we eat, from fruits and vegetables to eggs and meat. Fish are no exception,” the institute confirms.

In an age of misinformation and disinformation, knowing where to turn can be incredibly challenging. One need only to search a few terms online to find there is as much evidence for something as there is against. This is where Schutt believes her organisation and its members can help: “GOED and our member companies are trying to educate people about the benefits of seafood, the nutrients to look for, but also to consider omega-3 supplements as an alternative or addition.” In the public health realm, she believes others, such as dietitians, could be playing their part too by educating people on how to buy and prepare these food options.

Where else to look?

At a 2019 event, a pioneer in plant biotechnology and a flagship leader at Rothamsted Research, Professor Jonathan Napier, told delegates of the work he and his team had been doing in genetically modified food trials in the UK. Napier said they had been studying the performance of metabolically engineered oilseeds to accumulate omega-3 fish oils. “We have been evaluating the possibility of producing omega-3 LC-PUFAs in different transgenic hosts to provide a sustainable source of these important nutrients, and specifically to meet the needs of the aquaculture sector,” he said.

He added that effort to metabolically engineer plants with the primary algal biosynthetic pathway for LC-PUFAs had been successful in Camelina, shedding light on what constrains the accumulation of the fatty acids in non-native hosts. “The use of lipidomics has allowed us to identify further metabolic bottlenecks in the transgenic pathway, ultimately leading to the breakthrough production of a transgenic oilseed crop, which contains up to 30% omega-3 LC-PUFAs in its seed oil.” While their work was not complete, the audience was told that the omega-3 trait represented “probably the most complex plant metabolic engineering to undergo field-trials to date”.

The notion that oils derived from genetically modified plants can replace fish oil as a source of long-chain n-3 polyunsaturated fatty acids remains under investigation by Napier, alongside other closely related research. But while he and his colleagues continue their research, it is clear that humans need to do much more to harness the advantages of such nutrionally valuable produce.

Schutt says there are already some foods that have been formulated to include EPA and DHA omega-3s such as milk, eggs and even buttery spreads. However, she adds that one cannot depend on fortified foods to deliver all their EPA and DHA needs since the fortification levels are so low, but every little bit does help. “EPA and DHA omega-3s are in every cell of the body. They are important for cardiovascular health because they may help lower triglycerides, maintain healthy blood pressure, reduce the risk of heart attack and reduce the risk of coronary heart disease. They are also critical for brain and eye health and development, and for prenatal and maternal health,” she says.

“More than 80% of people worldwide are not getting enough EPA and DHA omega-3s. Even if people did eat two to three servings of fish per week, they still likely won’t reach the levels needed for cardiovascular health and risk reduction,” she continues. It is because of this, and because food science has not yet found the holy grail of modified or artificial essential oils, that dietary supplements are so important. “A daily supplement will ensure you’re getting what you need for overall health, including heart health,” Schutt concludes.