Omega-3

Omega-3 fatty acids are a family of polyunsaturated fatty acids which are essential for body and brain health, but which the body cannot make for itself, and are needed as part of a healthy diet. They are structurally different from the Omega-6 essential fatty acids, and the body cannot convert one into the other. Most people are deficient in both Omega-3 and Omega-6 fats, though it is the Omega-3 fatty acids that are particularly lacking in the avergae diet, and we should aim for an equal amount of both for optimum health.

Alpha-linolenic acid (ALA) can not be made by the body, and is essential for health, and so must be obtained from the diet. However, even more importantly, the body breaks a small amount of this ALA down into the most important Omega-3 fatty acids, eicosapentaenoic acid (EPA) and then into docosahexaenoic acid (DHA).

ALA is obtained in the diet from seeds, and the best sources are flax seed (also called linseed), hemp and pumkin seeds. Between 3 and 10% of ALA is converted by the body into the EPA & DHA you need. Meat from cows and sheep is also a reasonable source of ALA, but is much reduced in intensively reared farm animals which are not fed on grass. Cereals also contain some, as do green leafy vegetables.

EPA and DHA are also found in the diet, and the best sources are from the fish oil contained in oily fish such as mackerel, herring, cod, tuna and salmon. EPA & DHA become more concentrated the higher up the food chain we go. Small fish eat plankton which contains ALA. They convert some of this to EPA & DHA, and these are eated by larger fish which concentrate the EPA & DHA even more. However this only applies to wild fish, and farmed fish such as salmon is not fed in the same way does not have such high levels of beneficial omega-3 fats. Fish Oil supplements are extracted from the flesh of oily fish, and contain the beneficial Omega-3 fish oils in a form that allows you to take a higher dose than in oils extracted from fish livers, such as cod liver oil, which also contains vitamin A and vitamin D, which are toxic if you have too much, and this limits the amount of oil you can take. 

We all need to increase the omega-3 fatty acids in our diet as we are not getting enough of it to maintain our health, but just as important we need to balance this with the other group of essential fatty acids, the omega-6 group, which is usually present in our diets in too great a quantity, and the balance between the two is getting worse. The ideal balance is an equal amount of omega-3 and omega-6 in the diet, and currently the average ratio is about one part omega-3 to six parts omega-6.

Omega-6 fatty acids are derived from linoleic acid, which is an essential fatty acid which the body can not make, and which must be obtained from the diet. Some of this is broken down in the body to form either arachidonic acid or gamma-linolenic acid (which is the active ingredient of evening primrose oil). Omega-3 fatty acids are derived from alpha-linolenic acid.

Changing dietary and cooking patterns have reduced the amount of butter and lard used in prepared foods in favour of vegetable oils such as sunflower and corn oils which have a longer shelf life. Unfortunately these have very unbalanced ratios of alpha-linolenic to linoleic acids, giving a high level of omega-6 and a low level of omega-3 fatty acids. This imbalance increases the chance of getting heart disease, some types of cancer, and tends to make any inflamatory diseases worse. Omega-6 fatty acids compete with omega-3 for absorption by the body, and so an excess of them actually reduce the body's ability to absorb the omega-3 fats.

And it gets worse. Another popular ingredient made from vegetable oils by hydrogenation is margerine and hydrogenated vegetable oil. Many of these contain trans-fatty acids. These products are popular with the food industry because they have a long shelf life and a melt-in-the mouth type of texture, and are used to make cakes, biscuits, snack foods and take away fast food. Unfortunately they are bad news for your health because they interfere with the body's ability to metabolise alpha-linolenic acid into EPA & DHA. This further reduces the availability of omega-3 fatty acids in the body, even from good food sources such as flax seed, and shows the benefit of obtaining EPA & DHA from fish or fish oils. Trans fats also make your cholesterol levels worse by increasing LDL (bad cholesterol) and reducing HDL (good cholesterol) levels, and they have been consistently linked to heart disease, cancer and diabetes, so reducing these as much as possible from your diet will benefit your health. 

Omega-3 fatty acids are essential during pregnancy for brain development of the unborn child, though great care must be taken to avoid toxic polutants in fish or supplements. (See the sections on fish oil and pregnancy for more details).

Omega-3 fatty acids are essential for children's brains for continued normal brain development . Low levels have been linked with ADHD (Attention-Deficit/Hyperactivity Disorder), dyslexia, dyspraxia and autism. Eye Q supplements have been notably used in the Durham Trial where significant improvements were obtained in concentration and behavoiur leading to improved school results.

Omega-3 fatty acids are essential for adult brains, and levels are reduced in depression, schizophrenia and memory disorders such as dementia and Alzheimer's disease, and positive results have been obtained in some trials by diet and supplements.

Omega-3 fatty acids reduce the risk of having a heart attack, and are now regarded as essential for anyone who has had a heart attack, as they significantly help to prevent a further attack. They help to achieve this in several different ways, as they have a blood thinning effect which reduces the chances of blood clots which cause heart attacks and stroke, lower the tryglyceride fat content of blood, and reduce the furring up of the blood vessels with atherosclerotic plaque.

Omega-3 fatty acids are useful in joint problems and some inflamatory conditions (See the sections on fish oil and cod liver oil for more details).

Omega-3 fatty acids have protective effects against some common cancers, and current evidence suggests they are especially associated with cancers of the breast, colon and prostate.

Omega-3 fatty acids protect against age related macular degeneration, together with other nutritional factors. 

Omega-3 supplements are popular with people who do not eat enough oliy fish, but who want to protect themselves against a lack of omega-3 in their diet. It is best to buy a good quality supplement, as then you are sure that any contamination is kept at a very low level. There are specialist supplements for children and to be taken during pregnancy. (See the sections on fish oil and pregnancy for more details).

Antioxidants are important in addition to omega-3 supplements as they are needed by the body to prevent oxidation of omega-3 and omega-6 fatty acids, because if the body does not have enough antioxidants these fats can become oxidised and rancid, and these breakdown products acn cause damage to the body by free radical attack. Antioxidants are contained in fruit and vegetables, and it is important to eat plenty of these if you are using fatty acid supplements. You may also wish to boost their intake by taking antioxidant supplements such as vitamin E and vitamin C.