Omega-3 Fatty Acids

Omega-3 fatty acids are a family of good fats that are essential for your health, but are sadly lacking in the modern diet, which can cause medical problems.

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Related Pages : Omega-3 Supplements For Children : Cod Liver Oil : Flax Seed Oil : Pregnancy : Joint Care : Osteoarthritis : Rheumatois Arthritis : Arthritis & Rheumatism :
Related Articles : Omega-3 Fatty Acids : Omega-3 Fatty Acids For Children : Flax Seed Oil & Flax Seeds ::

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What Are Omegs-3 Fatty Acids?

Omega-3 fatty acids are a family of polyunsaturated long chain 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. Omega-3 fatty acids are lacking in the average diet and this is causing health problems.

Alpha-linolenic acid (ALA) is an omega-3 fatty acid obtained in the diet from green leafy vegetables and certain seeds and meat products. However, ALA isn't directly used by the body. It must firstly be metabolised into eicosapentaenoic acid (EPA) and then some into docosahexaenoic acid (DHA). Unfortunately only between 3 and 10% of ALA is converted by the body into the EPA & DHA you need, and this amount is reduced in diabetes, schizophrenia and some other disease states and where there is an excess of omega-6 fatty acids present in the diet, which is the norm in most western diets, or when trans-fats are consumed.

Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA) are the omega-3 fatty acids that the body uses, and they play a vital role in many body processes.

Health Benefits Of Omega-3 Fatty Acids

The health benefits of omega-3 fatty acids were highlighted in the 1970's by researchers studying the Greenland Eskimos. They consumed large amounts of fat from seafood, but displayed virtually no cardiovascular disease. The high level of omega-3 fatty acids eaten by the Eskimos reduced triglycerides, heart rate, blood pressure, and atherosclerosis.

Omega-3 fatty acids have the following health benefits :

• Heart & Circulation . 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, improve cholesterol levels and lower the tryglyceride fat content of blood, and reduce the furring up of the blood vessels with atherosclerotic plaque.They may also help with Reynaud's disease.
• Blood Pressure . Some studies have shown a reduction in blood pressure with increased use of omega-3 fatty acids.
• Varicose Veins. Omega-3 fatty acids help blood flow and also help break down clots and scar formation in varicose veins.
• Brain & Nervous System . Omega-3 fatty acids are essential for brain development at all ages, though this is particularly important during pregnancy and childhood . Low levels of omega-3 in children have been linked with ADHD (Attention-Deficit/Hyperactivity Disorder), dyslexia, dyspraxia and autism. Omega-3 fatty acids are also essential for adult brains, and levels are reduced in depression , schizophrenia, agression and memory disorders such as dementia and Alzheimer's disease , and positive results have been obtained in some trials by increasing omega-3 intake with diet and supplements.
• Joints. Omega-3 fatty acids can be useful in osteoarthritis and rheumatoid arthritis .
• Cancer. 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.
• Eyes. Omega-3 fatty acids protect against age related macular degeneration, together with other nutritional factors.
• Inflammation.Omega-3 fatty acids produce anti-inflammatory chemicals in the body which can help with some inflammatory diseases such as rheumatoid arthritis , asthma, inflammatory bowel disease, psoriasis and lupus. Inflammation is also a major factor in atherosclerosis which causes furring-up of blood vessels, heart attacks and strokes.
• Osteoporosis . Omega-3 fatty acids may help to increase calcium levels in bone and help minimise osteoporosis.
• Immune System . Omega-3 fatty acids are essential for immune system functioning.

Omega-3 Fatty Acids In The Diet

Alpha-linolenic acid (ALA) is obtained from the diet from green leafy vegetables and certain seeds. It is part of the green chlorophyll structure in plants, and is obtained by eating green leafy plants. It is also obtained from eating the meat of grass fed animals, such as cows and sheep, though intensively reared animals fed on grain have much lower levels. Some cereals are good sources of ALA, such as flax seed, rape seed, pumpkin, soya, walnut and hemp. Eggs and milk are produced with a higher ALA omega-3 content by feeding ALA rich seeds to chickens and cows.  However, ALA isn't directly used by the body. It must firstly be metabolised into eicosapentaenoic acid (EPA) and then some into docosahexaenoic acid (DHA). Unfortunately only between 3 and 10% of ALA is converted by the body into the EPA & DHA you need, and this amount is reduced in some disease states.

Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA) are obtained in the diet by eating oily fish, or by the body converting ALA into EPA & DHA. Fish obtain their omega-3 fatty acids from ALA in plankton. Small fish eat the plankton and convert the ALA into EPA & DHA. Larger fish eat the smaller fish and concentrate the ALA & DHA into their bodies. The higher up the food chain you go the more these are concentrated. The best sources of ALA & DHA are from oily fish such as mackerel, herring, cod, tuna and salmon. However this only applies to wild fish, and farmed fish such as salmon are normally fed on grain and do not have the same levels of beneficial omega-3 fats. Fish oils 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.

The current dietary recommendation for fish is that  you should eat two portions of fish a week, and one of these should be of oily fish. There is concern that much fish is now contaminated due to pollution of the sea. Persistent organic pollutants such as dioxins & PCB's (polychlorinated biphenyls) and heavy metals such as mercury are now widely found in fish. These toxins accumulate over time in the body and are difficult to remove. This is especially serious during pregnancy as they may be toxic to the unborn baby. Due to these toxins the maximum amount of oily fish recommended for girls and women who may one day have a baby is two portions a week. Women who are pregnant are recommended to continue eating up to two portions of oily fish a week as the omega-3 fatty acids are essential for the brain development of the unborn child. For women who will not have another baby and for men, the maximum recommended is four portions of oily fish a week.

Balancing Omega-3 & Omega-6 Fatty Acids

The balance of omega-3 to omega-6 fatty acids  consumed is important for optimal health. The ideal balance is thought to be between 1:1 and 1:4 of omega-3:omega-6. Currently the average ratio is about one part omega-3 to between 10 and 30 parts omega-6. 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. 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.

An excess of omega-6 fatty acids is currently causing health problems for many people because the inflammatory nature of the omega-6 breakdown products isn't being offset by the anti-inflammatory nature of the omega-3 breakdown products. Inflammation is a common symptom of many diseases including as arthritis , asthma and lupus. Inflammation is also important in the furring-up of blood vessels in atherosclerosis, which leads to heart attacks and stroke.

Don't overdose on fish oils. Increasing omega-3 fatty acids is important, but you also need to look at obtaining a balance of healthy omega-6 fatty acids from the diet, as much of this is of low food value in the general diet due to food processing, which also produces trans-fats, which are bad news for your health. Cutting down on processed foods and eating high quality omega-6 foods such as seeds, seed oils and nuts is important.

The Danger of Trans-Fats

Trans-Fats are a by-products of the processing of vegetable oils when they are hydrogenated to produce margarine. Hydrogenated vegetable oils 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 ALA 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. 

Taking Omega-3 Supplements

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 fish oil supplement which uses fish from unpolluted waters to minimise contamination from pollutants. There are specialist omega-3 supplements for children and omega-3 supplements for pregnancy. Cod liver oil supplements contain omega-3 fatty acids together with vitamin A and vitamin D, but taking too much of these vitamins can be toxic, and so this limits the amount of omega-3 you can safely obtain from them..

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 can 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 your intake by taking antioxidant supplements such as vitamin E and vitamin C .

Cautions

Omega-3 fatty acids can thin the blood and taking fish oil supplements should be medically supervised if you are taking blood thinning medication such as warfarin or aspirin. They should also not be taken for two days before to two days after surgery.

Fish oil supplements may increase fasting blood sugar levels in Type2 Diabetes and this should be medically monitored.

Some fish may contain higher levels of pollutants such as heavy metals, dioxins and PCB's and these should not be eaten by pregnant women or children. It is best to consult further references for up to date guidance on this.

Further Information & References

Omega-3 Fatty Acids - Wikipedia
Omega-3 Fatty Acids - University Of Maryland Medical Centre
Fish & Shellfish - UK Food Standards Agency

See Also Fish Oil Products Fish Oil Information Related Pages : Omega-3 Supplements For Children : Cod Liver Oil : Flax Seed Oil : Pregnancy : Joint Care : Osteoarthritis : Rheumatois Arthritis : Arthritis & Rheumatism : Related Articles : Omega-3 Fatty Acids : Omega-3 Fatty Acids For Children : Flax Seed Oil & Flax Seeds ::