The long-chain polyunsaturated fatty acids (DHA and EPA) found in oily fish have a particularly flexible chemical structure which allows them to be absorbed in to cell membranes and nervous tissue.
Because of this unique structure they're very important for human health. Their role in curbing inflammation is probably the reason why they can protect against a wide range of allergies, inflammatory diseases such as arthritis and irritable bowel, some cancers, heart disease and even Alzheimer's disease.
Additionally, EPA has blood-thinning properties, which give further cardiovascular protection. Some researchers believe that we evolved on a diet uniquely high in these fatty acids, which then permitted our brains to develop in such a sophisticated way.
Children in particular may benefit from these fatty acids early in life when they're being incorporated into brain and eye structure. So important are these omega-3s to babies that human breast milk is particularly rich in them. Research is also showing that learning and behavioural conditions, such as dyslexia, dyspraxia and Attention Deficit Hyperactivity Disorder (ADHD), can be significantly improved in some children by supplementing omega-3s.
Finding your Fish...Oils...
Fish with medium amounts include halibut, smelt, shark, oyster, swordfish and trout.
Fish with low amounts include tuna (canned in any way as it is defatted before canning), bass, bream, cod, coley, prawns, mussels, haddock and of course, fish fingers and fish and chips.
It's recommended to eat two portions (150g/6oz) of fish weekly, with one portion being oily fish. Pregnant woman, however, are advised to avoid shark, swordfish and marlin, and limit tuna to one medium steak or two cans per week because of problems with pollution in fish higher up the food chain. Many people prefer to get their omega-3s from fish oil supplements (which are made from fish muscle meat or krill) rather than cod liver oil, as there is more risk of environmental contamination in liver oils. Cod liver oil is high in vitamin A and should be avoided if planning to conceive - too much can adversely affect the developing foetus.
Plant sources
Plant sources of omega-3 fatty acids can be turned, in the body, into the same long-chain structures as those found in oily fish, but this process is slow and not necessarily very efficient in some people (most likely those with allergies or learning difficulties).
Although fish remains the best source of these fatty acids, fish consumption has dropped by 50 per cent in the last fifty years.
Interestingly omega-3s are the most abundant fatty acids on the planet - found in all grasses and leaves:
-enriched eggs
-organic milk has two-thirds more omega-3s than ordinary milk
-flax oil and linseeds (flax seeds)
-canola (rape) oil
-pumpkin seeds or oil
-walnuts and walnut oil
-green, leafy vegetables
Don't forget that these important Omega-3 fats cannot be produced by the body and must be obtained from the diet - giving them the name - 'essential fats'.
