Why can’t we just eat more fish to source our omega-3?
Ideally we should be able to meet our needs through eating fish, though not all fish provide the same amount of omega-3. The flesh of oily fish such as sardines, salmon, pilchards and mackerel, is rich in long-chain omega-3 fatty acids and eating two portions of these fish per week can provide a daily amount of around 0.5g omega-3. Eating cod, or haddock or plaice (known as ‘white’ fish) won’t have the same benefits because these fish store their omega-3 fatty acids in their livers – not their flesh – and the liver is removed during the gutting process.
Whilst tinned tuna is often a popular choice for fish eaters, the oil is removed during the canning process and has little benefit on long-chain fatty acid status, but yet it retains levels of undesirable pollutants. This seems to be a fact not well-known by the general public. Whilst we may consider that we eat fish reasonably regularly, the UK population as a majority, however, does not consume enough oily fish to ensure that dietary levels are met.
Whilst increasing fish consumption could have heath benefits, there are concerns associated with fish and shellfish consumption and contaminants such as methylmercury, dioxins and polychlorinated biphenyls (PCB) – all pollutants from industrial processes. Those fish that sit higher in the food chain are likely to contain higher levels of contaminants and some larger fish such as marlin, swordfish and tuna are becoming increasingly unsafe to eat.
Why purified supplements may be an alternative to eating more fish
1. To make sure you are getting a rich supply of omega-3 when eating fish you really need to be eating oily fish such as mackerel and salmon. Whilst 2 portions weekly provides the ideal daily dosage for maintaining general health, this level of consumption is not adequate for clinical therapeutic purposes.
2. White fish, whilst eaten more commonly, tends to be low in omega-3 levels and doesn’t provide sufficient omega-3.
3. Some fish stocks, particularly larger long-lived species, are high in contaminants, meaning we are restricted as to how much we can eat and how often.
4. Fish contains Vitamin A, which is a fat-soluble vitamin and is stored in the body. High levels of Vitamin A have been associated with liver damage. Purified oils removed Vitamin A, enabling high quantities of omega-3 EPA to be derived, without risking Vitamin A toxicity.
5. Purified concentrated fish oils provide an easy and safe alternative to eating oily fish, meaning that higher doses can be taken for therapeutic purposes without exposure to harmful chemicals.