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Know your Omega 3s

EPA, DHA and Short-chain polyunsaturated fatty acids

Maintaining sufficient levels of ‘good fats’ in the diet has been associated with a plethora of health benefits, from reduced cardiovascular disease, healthy brain function and balanced mood, to reduced rates of cancer and even enhanced longevity. It’s no wonder that so much attention has been drawn to the benefits of increasing certain types of these fats in the diet. Along with the increasing scientific evidence, numerous ways of enhancing omega-3 intake now fill the shelves. Quite apart from increasing oily fish intake (a very valid solution as long as you restrict this to two portions of oily fish weekly), aisles are now filled with foods fortified with omega-3 such as yoghurts and bread, and there are numerous different types of omega supplements. When we say numerous, we mean products containing active ingredients (EPA/DHA) ranging from 10% to 90% – no wonder, therefore, that consumers have a mixed impression about omega-3 fatty acids and the health benefits these fats are purported to offer. We hope that the information below will clarify the science behind the biological roles that these fats play.

1. Short-chain fatty acids

Short-chain fatty acids are commonly labelled ‘essential fatty acids’ (EFAs) because they are parent fatty acids (ALA at the top of the omega-3 family and LA at the top of the omega-6 family) and cannot be manufactured by the body – hence we must obtain them from our diet. It is from these two parent EFAs that the long-chain omega-3 and omega-6 fatty acids are derived, through enzyme elongation reactions in the body. Most health benefits are derived from the long-chain fatty acids such as EPA, important for neurological function, as well as byproducts of EPA called eicosanoids – important anti-inflammatory substances including prostaglandins and leukotrienes. The majority of short-chain fatty acids are utilised as fuel and some go on to be metabolised to long-chain fatty acids (which are the precursors to eicosanoids). It is now well-known that these conversions are not very efficient in many people and the actual amounts of long-chain fats derived from short-chain fats tend to be very low. This is due to changes in the modern lifestyle and diet – for example, only a very small percentage of the parent omega-3 fatty acid ALA consumed in the diet is converted to the more important long-chain fatty acids such as EPA, DHA, and ultimately to the anti-inflammatory eicosanoids. You can overcome this poor conversion rate by ensuring your diet is rich in long-chain fatty acids, effectively by-passing the ‘blocks’ posed by viruses, nutrient deficiencies, trans fats, alcohol and other inhibiting factors such as stress. Short-chain fatty acids are plant based fats, the benefits of which are quite different from long-chain fats typically derived from fish, despite often being grouped together on the shelves with fish oils. Plant-based oils such as flaxseed tend to much cheaper than fish oils, which can also lead to a misconception about ‘value for money’. Plant oils are rich in ALA (the parent omega-3 fatty) acid, which does make them suitable for vegetarians, but the body still has to undertake a series of lengthy conversions before they become the more useful long-chain fatty acids such as EPA and DHA. Because humans aren’t efficient at converting short-chain fatty acids to long-chain fatty acids, plant oils cannot offer the same health benefits as fish oils – so, unless you are vegetarian it is advisable to seek out a purified and concentrated EPA supplement with the ‘active’ fatty acid already in its bioavailable form. Most foods fortified with omega-3 tend to be those containing plant-based omega-3 fats and, for the same reasons as discussed above, will not provide brain-boosting and heart-protecting benefits associated with fish oils. For vegetarians, vegans and those allergic to fish seeking to boost their EPA omega-3 levels, a newly available source of vegetarian omega-3 provides a more effective precursor to EPA than the commonly available flaxseed oil, containing the parent omega-3 ALA (which must be converted through a series of enzyme reactions before reaching EPA in the body). Echium Seed Oil found in Echiomega, unlike flaxseed oil, contains SDA – a closer relative to EPA, which converts more efficiently to EPA and its anti-inflammatory derivatives.

2. Cod liver oil

Cod store the majority of their omega-3 in their livers and relatively little in their flesh. Originally a by-product of the fishing industry, cod were first of all filleted before the liver was pressed for its oil, known to be rich in omega-3. The liver, however, is also the site of storage of vitamin A, though important for new cell growth, healthy skin, hair, and tissues, vitamin A is toxic in high doses. The liver also functions to neutralise toxic substances and so can act as a reservoir for contaminants such as methylmercury, dioxins and PCBs. Due to its high vitamin A content and, more recently (through contamination of the oceans), pollutants, cod liver oil is less safe now than when it was consumed by our grandparents! Seemingly cost-effective, the low amounts of EPA found in cod liver oil precludes this widely available product from offering the heart and brain health benefits that omega-3s are famed for.

3. Generic fish oil

This refers to oil that has been extracted from the flesh of fish and filtered to remove contaminants to legal limits, but not molecularly distilled or concentrated. They tend to be easy to spot on the shelves, as they typically contain 180mg EPA and 120mg DHA per 1000mg of fish oil and are relatively cheap to buy. In other words they amount to about 18% and 12% of EPA and DHA, compared with our concentrated EPA in PHARMEPA rTG-EPA 90, which contains over 90% concentration EPA.

4. Pharmaceutical-grade oil

These oils undergo rigorous molecular distillation and/or concentration. Molecular distillation ensures that the oil is free from contamination and from vitamin A. By concentrating the EPA, the amount of physiologically active EPA in the final product is increased and uptake in the body is enhanced. PHARMEPA rTG-EPA 90 for example, comprises 90% rTG EPA concentrate, in a pure, safe and well tolerated format for clinical dosing of 1-2 g daily.


  1. Natural triglyercide oil. This is what you get when you “squeeze” the whole fish and extract the natural oil from it. It is the closest to eating fish oil in its natural form, and is highly bioavailable. The drawback of this form is that, because it’s not concentrated, it usually has low levels of the active ingredients EPA and DHA. And because it isn’t purified, it can have high levels of contaminants such as heavy metals, PCBs, and dioxins. This form is found in most standard fish oil supplements (see Generic Fish Oil above)
  2. Ethyl ester oil. Occurs when natural triglyceride oil is concentrated and molecularly distilled to remove impurities. The ester form is still in a semi-natural state because it is the result of a process that naturally occurs in the body. The advantage to this form is that it can double or triple the levels of EPA and DHA.
  3. Synthetic triglyceride oil. With technological advancements and increased demand for EPA, there is now an alternative that offers the superior bioavailability of natural triglyceride fat molecules with the high concentration active doses of ethyl-esters – known as ‘re-esterified triglycerides’ (rTG). After the oil is concentrated in its ethyl-ester form, it is converted back to a triglyceride structure by re-attaching the fatty acids to a glycerol backbone. This produces an oil with high omega-3 EPA concentrations (like ethyl-ester form), but simultaneously enhances its absorption and delivery like the natural triglyceride oils. Studies show that rTG forms of omega-3 are so bioavailable that they offer greater absorption without the need for dosing with or after food, increasing the omega-3 index faster and more effectively than any other form of omega-3 .For therapeutic use in specific health conditions, or for those serious about their health, rTG is the gold standard – thus, it is also more expensive but has been proven to raise the omega-3 index to a greater extent and more rapidly than any other form of omega-3


Important considerations when choosing a fatty acid supplement:

  • Not all oils are the same. Omega-3  fatty acid products offer different benefits and you tend to get what you pay for. Products offer various ratios of EPA and DHA, though some (like ours) offer pure EPA to maximise its benefits in the body. Without the competing actions of DHA, EPA is free to exert its potent anti-inflammatory actions, offering numerous health benefits
  • Oils differ in their concentration. Low concentration oils are cheaper and therefore give an unrealistic impression that they are good value for money. Igennus EPA is concentrated and therefore offers a cost-effective source of EPA, though the initial outlay is likely to be more. It’s sensible to read the label to see how many milligrams of the important fatty acids (EPA) you’re getting for each pound you pay, as well as how much EPA there is in excess of DHA. Recent evidence suggests that in combined EPA and DHA oils, the benefits are derived from the excess amounts of EPA. In the example cited above, the ‘free’ amount of EPA is only 60 mg (180 mg EPA versus 120 mg DHA).  A nice advantage of concentrated fatty acid supplements is that they also contain lower amounts of unnecessary, biologically ‘redundant’ fats compared with generic oils.
  • Be aware of the difference between short-chain plant based fatty acid oils and long-chain fatty acids derived from fish oil. Supplements containing long-chain fatty acids avoid the inefficient elongation processes, which means they offer superior brain-boosting and heart-protecting benefits. If you are vegetarian or vegan, the omega-3 SDA offers enhanced rates of conversion to EPA (up to fives times more than ALA found in flaxseed oil); SDA is found in plentiful quantities in Echium Seed Oil, the oil found in our product Echiomega.
  • Oils differ in their purity – some contain higher levels of contaminants than others. Only truly pure oils will be contamination-free. Oils sourced from larger longer living fish will contain the highest level of contaminants because they are higher in the food chain and pollutants accumulate in their flesh. Oils should ideally be sourced from fish lowest in the food chain. Small, short-lived fish also tend to be more sustainable.

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