Omega-3 fatty acids have been recommended as a dietary supplement for decades due to their potential benefits for heart health, brain function and anti-inflammation. They are naturally found in fish oil and vegetable oils. However, their benefits are unproven and their supplementation is not scientifically supported. It is little known that their harvesting has devastating consequences for the marine ecosystem. In a very worth reading article, which I would not like to withhold from the dekoblog, Prof F.R. Eberli points out this terrible fact.
Whole lotta Omega-3 going on. Kizimkazi, Sansibar.
The omega-3 hypothesis
It states that a high proportion of omega-3 fatty acids, which are ingested with a diet rich in fish, protects against coronary artery disease (circulatory disorders of the heart due to arteriosclerosis). The Inuit in Greenland serve as an example for this hypothesis, as they suffer from coronary artery disease less frequently than would be expected despite eating a high-fat diet.
Some biochemistry
Fats and oils consist of unbranched long-chain fatty acids. Unsaturated fatty acids contain double bindings, which means that their carbon atoms (C) are not completely occupied by hydrogen atoms: they are therefore unsaturated. The most important representatives are alpha-linolenic acid (ALA), marine eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). ALA comes from plants and nuts, EPA and DHA mainly from fatty marine fish. The body cannot synthesise these fatty acids on its own. They are therefore considered essential. However, it is important to note that the human organism can produce EPA and DHA from plant-based ALA, which explains normal levels in vegetarian and vegan diets. One spoonful of rapeseed oil is sufficient to cover the daily supply of omega-3.
Possible effects on the circulation
These include the incorporation into cell membranes and the modulation of membrane channels and receptors, which should have a favourable effect on the heart rhythm and the autonomic nervous system; an anti-inflammatory effect, which should reduce the formation of atherosclerosis and the regulation of HDL ("good") and LDL ("bad cholesterol"), which would also have a favourable effect on atherosclerosis.
Effects outside the circulatory system
Because of the possible favourable effects mentioned above, omega-3 supplements have been studied in various diseases. Unfortunately, they have not shown any benefit in the following diseases either: depression, Alzheimer's dementia and other forms of dementia, migraine, breast cancer, prostate cancer, rheumatoid arthritis and non-alcoholic fatty liver disease. They also have no benefit as a dietary supplement during pregnancy, although the mother needs to synthesise EPA and DHA from plant ALA for child development and it could be assumed that supplementing omega-3 fatty acids from marine fish could have a beneficial effect.
The hype...
In the USA and Europe, the consumption of omega-3 fatty acid supplements has increased tenfold in the last ten years and is set to rise further. Despite a lack of clear evidence for the claimed health benefits, the appeal of natural products in the prevention and cure of diseases seems unbroken. With a turnover of over 33 billion in 2016, the fish oil industry funds studies, frames them positively and uses marketing strategies to sell even flawed observational studies as truth. The targeted stirring of desires for a healthy, long life through psychologically skilful marketing reinforces this trend. Omega-3 fatty acids from marine animals are not only advertised as a valuable additive in food supplements, but also in drinks and foods. They are even used in veterinary medicine, for example to supposedly improve the quality of dogs' fur.
... and its ecological toll
The omega-3 fatty acids EPA and DHA are synthesised by phytoplankton and algae with the help of the energy of the sun in the oceans. They make their way up the food chain to anchovies, sardines and herring etc. However, even the lipids in marine fish only contain a small proportion of omega-3 fatty acids. The continuing demand for omega-3 fatty acid supplements and omega-3-rich fish has led to more than an eighth of the world's fish catch being used for the production of fish oil or feed for aquafarming. As sardines, anchovies and herrings in particular, which provide food for many larger fish, are caught using complex technology and close-meshed nets, not only are fish stocks reduced, but the ecological balance is destroyed. Omega-3 is also enriched in the liver of sharks. There is now a well-developed, large shark fishing industry that also specifically hunts protected sharks, as their livers are particularly rich in omega-3 fatty acids.
Unfortunately, the idea of eating fat-rich fish instead of omega-3 supplements also raises concerns. The ecological damage caused by the increased consumption of large marine fish and overfishing is comparable to that of the fish oil industry. Cod is highly endangered, tuna are acutely threatened with extinction. Aquafarming, mainly for salmon, requires marine proteins, which has resulted in increased krill fishing in the Antarctic Ocean. The removal of krill jeopardises the Antarctic ecosystem. Aquafarming is animal-unfriendly, pollutes the environment and has a significant negative impact on natural fish stocks, especially wild salmon.
The bottom line
Eberli concludes that the omega-3 fatty acid hypothesis is not tenable on the basis of comprehensive evidence. He argues against further studies and points out that supplementing our diet with omega-3 fatty acids from fish does not provide any health benefits. The plant-based omega-3 fatty acids in our diet are sufficient, he says. Eberli emphasises the need to move away from the demonstrably false omega-3 hypothesis, particularly because of its devastating ecological consequences for the marine ecosystem.
There is absolutely nothing to be added to his statement.
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