What types of omega-3 are there?

Much attention has been drawn to the benefits of increasing omega-3 fatty acids in the diet, either through direct fortification of foods such as yoghurts and bread, or through supplementation. It is a complex area, however, and therefore not surprising that there is some confusion as to the best sources of omega-3 fatty acids and their various roles in keeping the body in balance.

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 labeled ‘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 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-6 fatty) acid, which does make them suitable for vegetarians, although 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 in converting short-chain fatty acids to long-chain fatty acids plant oils cannot offer the same health benefits as fish oils, so unless you’re vegetarian it’s advisable to seek out a purified and concentrated fish oil. 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 omega-3 levels, a newly available source of vegetarian omega-3 provides a more effective precursor to EPA than the commonly available flaxseed oil which contains the parent omega-3 ALA (which must be converted through a series of enzyme reactions before reaching EPA in the body). Echium seed oil, unlike flaxseed oil, contains SDA – a closer relative to EPA which therefore converts more efficiently to EPA and its anti-inflammatory derivatives.

2. Cod liver oil.

Until the 1950s school children were routinely given cod liver oil because of the benefits associated with immunity, inflammation and cardiovascular health. So why exactly has this stopped? Cod store the majority of their omega-3 in their livers and relatively little in their flesh and cod liver oil was originally a bi-product of the fishing industry. When a cod was filleted the liver went off to be pressed for its oil, known to be rich in omega-3. The liver is also the site of storage of vitamin A, important for new cell growth, healthy skin, hair, and tissues but is toxic in high doses. The liver also functions to neutralize toxic substances and so can act as a reservoir for contaminants such as methylmercury, dioxins and PCBs. Cod liver oil can therefore be high in vitamin A and, more recently (through contamination of the oceans), in pollutants, making it less safe than when it was consumed by our grandparents!

3. Generic fish oil.

This refers to oil that has been extracted from the flesh of fish and filtered but not molecularly distilled or concentrated. They tend to be easy to spot on the shelves as they will generally contain 180mg EPA and 120mg DHA per 1000mg of fish oil and will be relatively cheap to buy. In other words they amount to about 18% and 12% of EPA and DHA, compared with our concentrated oils in Vegepa, which contains over 70% concentration EPA.

4. Pharmaceutical-grade oil.

These oils undergo rigorous molecularly distillation and/or concentration. Molecular distillation ensures that the oil is free from contamination and from vitamin A. By concentrating the oil the amount of active ingredients in the final product is increased. Vegepa for example comprises of 70% EPA fish oil and is the purest, most concentrated oil on the market.

Important considerations when choosing an omega oil:

1. Not all oils are the same. They offer different benefits and you tend to get what you pay for.

2. Oils differ in their concentration. Low concentration oils will be cheaper and therefore give an unrealistic idea of being good value for money. It’s a good idea to read the label to see how many milligrams of the important fatty acids (like EPA) you’re getting for each pound you pay. Our oils are concentrated and therefore offer a cost-effective source of omega fatty acids. Generic oils which contain lower levels of the active ingredients also contain higher levels of unnecessary fats.

3. Be aware of the difference between short-chain plant based fatty acid oils and long-chain fatty acids derived from fish oil. Long-chain fatty acids offer the brain-boosting and heart-protecting benefits.

4. Oils differ in their purity – some will have higher levels of contaminant 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.