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Omega 3's and GM plants: Innovations in aqua/agriculture

  • Writer: digitalflynn
    digitalflynn
  • Jul 7, 2021
  • 6 min read

Updated: Jul 8, 2021

“Contrary to popular belief, there are not plenty more fish in the sea.” – Prof. Jonathan Napier


From 6th – 8TH July, The Nutrition Society held their annual Summer Conference, this year looking at Nutrition In A Changing World. Topics ranged from the food system and climate change, to novel farming techniques, to a review of intermittent fasting (with a focus on Ramadan) and much more.


Professor Jonathan Napier, from Rothamsted Research, Hertfordshire (UK), delivered a particularly thought provoking talk on day one: Making fish oils in plants – a sustainable, terrestrial source of omega-3 long chain polyunsaturated fatty acids.


First off, what are omega-3’polyunsaturated fatty acids (PUFAs)? They are a group of essential fatty acids which the human body cannot produce on its own, we can only get them through diet. Omega 3 is a classification, it tells you where the double bond is on a particular polyunsaturated fatty acid. There are three types: ALA (Alpha-linoleic acid) which is found in plants, such as linseed, flaxseed, walnuts; DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid), which is found in animals such as fish and also algae. EPA has anti-inflammatory effects and is needed for cardiovascular health and can help lower triglycerides. It can be converted into DHA - essential for brain development. The omega 3’s found in plants are not the same form of omega 3’s found in fish oil. The EPA and DHA that you find in fish oil are 20 carbon or 22 carbon fatty acids with 5 or 6 double bonds. The omega 3 you find in plants like linseed are 18 carbon fatty acids with 3 double bonds and are not equivalent either functionally or even chemically as EPA or DHA.

The key here is the return for EPA and DHA levels in plants - it doesn’t matter whether it’s soy, palm or oil seed, it’s a NIL RETURN. Meaning none of the fatty acids in any of these plants make these long chain fatty acids. Deficiencies in EPA and DHA can not only cause skin dryness, brittle hair and nails, depression, joint pains, but over a dozen epidemiological studies have found that reduced intake of Omega-3 fatty acid (EPA and DHA) is associated with an increased risk in age-related cognitive decline, dementia and Alzheimer’s disease. Currently over 850,000 people are said to be living with dementia in the UK alone, costing the UK around £34.7 billion a year.


The current recommendation of Omega-3 is around 200-500mg of combined EPA and DHA a day for adults. For more information check out heartuk.org It’s main source is from oily fish such as salmon, trout, mackerel, sardines, pilchards, kippers and herring.


Jonathan’s Research:


Agriculture gets a bad reputation. People accuse it of being degrading of the environment and a huge contributor in climate change. And yet it’s responsible for feeding the globe. Aqua-culture is far more sustainable. Over 50% of fish consumed on the planet is produced by something called aqua culture. People assume that most of the fish they eat has been produced by fisherman, that it came from the ocean. It is mostly produced from fish farming and because of its sustainability, this will continue to grow. Whilst fish like salmon, trout and sea bream are easy to farm, there is one particularly difficult issue: they have to be given fish oil as part of their diet, otherwise they don’t develop properly and the product the consumer gets will not have any fish oils in it. This is a problem. Aqua culture demand is increasing as population is increasing. The fish oil fed to the fish is harvested from small fish species in the ocean that are not used for direct human consumption such as anchovies. The amount of fish oil in the sea is finite. How do you deal with an expanding demand in production with a limited resource? Aqua culture has become more sustainable but only through changing the diet of the fish. 30 years ago, fish in aqua culture were fed exclusively on fish oil. Now, the vast majority of what is being put into fish diets is vegetable derived/plant derived oil and plant protein. This does make things sustainable, but it’s also completely changed the nutritional profile of the fish in a way that people aren’t probably aware of. Plant oils don’t have EPA and DHA, fish oils do. Fish oil is a bit of a misnomer as fish do not make fish oils. Fish such as salmon, trout and sea bass cannot make fish oils because they do not have the metabolic capabilities to do that. Just like us, they are what they eat. In a course of 10 years, as the diets for these fishes were adapted from marine-based to plant based, reducing the amount of EPA and DHA by half. And this is in Scottish farmed salmon - considered to be the Gold Standard for the levels of the marine ingredients, for the levels of EPA and DHA.


A way to produce these omega 3 long chain PUFAs de novo is needed. Jonathan and his colleagues had this idea 25 years ago – to try and make omega 3 long chain PUFAs in a genetically modified (GM) plant. The idea was to take the genes form marine algae because it’s the marine microalgae that are the long chain PUFA’s in the environment* and put them into plants to subsequently feed the fish. This was harder than first thought. The pathway for making EPA and DHA (converting the plant fatty acids that are predominantly linoleic acid and ALA) involves multiple steps and conversions and lots of genes had to be inputted into plants. The genes had to be found and optimised and this was done with the help of programmable and synthetic biology.


*they are basically the base of the food web that allows these fatty acids to accumulate all the way up through different trophic levels through the food web and into things like fish and therefore humans.


Successful use of the Camelina plant has been implemented, with years of experimenting to both increase the omega-3 content and reduce the omega 6. Last year over 1.2 million camelina plants were grown in the US, UK and Canada – the power of

agriculture. You can read more here


FROM FIELD TO FJORD TO FORK


All these hurdles to get this to the consumer: GM regulation, intellectual property, business development, commercialisation – this has been more complicated that the metabolic engineering that they embarked on and it takes money and A LOT of time. GM foods are widely consumed and accepted now, but talking about the project and getting coverage in the media has helped spread the word positively. (You can read an article from the Telegraph here if you have a subscription The key question for the public is who is benefitting? Ultimately this research is helping the environment by making aqua farming more sustainable by not harvesting fish oil out of the ocean, plus it puts the much needed nutrients back in people’s diets. It is superior to other current approaches and it is proven to be successful from all the field trials done.


The innovative work Jonathan and his team has done is a very exciting advancement in the food and environmental world. As a nutritionist, my job is to always advocate a food first approach before recommending supplements. But if people aren’t getting the required amount of nutrients even when consuming the recommended amounts from food, what choice do we have? The fact our food sources may be less nutritious due to modern farming techniques is problematic at a time when non-communicable diseases caused by poor nutrition are so prevalent. We have more research to do to understand the extent of this reduction and its potential solutions.



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