lipid

Difference Between Omega 3 and Omega 6

د. حسين محمد جمعه
اختصاصي الامراض الباطنة
البورد العربي
كلية طب الموصل
2012

Both the omega-6 and omega-3 fatty acids belong to a group of polyunsaturated fats called 'essential' because they are necessary to life and to health yet we cannot make them in the body - they must be obtained from diet. They cannot be inter-converted and both must be present in the diet in a proper balance for good health.
Their differences lie in their chemical structure and their roles in the body.

As polyunsaturated fatty acids, both the omega-6 and the omega-3 families have more than one double bond in the carbon chain. All fatty acids in the omega-6 family contain their first double bond between the 6th and 7th carbon atoms (counted from the methyl (CH3) terminal carbon atom and the omega-3 family of fatty acids have their first double bond between the 3rd and 4th carbon atom.

Both families of fatty acids are vital components of membranes and are used by the body in the production of eicosanoids, a vast range of highly bioactive substances (prostaglandins, leukotrienes, and lipoxins) but the activity of these metabolites varies. For example, the eicosanoids derived from omega-6 are in general more active (or reactive) than those produced from omega-3 and omega-6 is aggregatory whereas oega-6 is pro-aggregatory.

Basically, the omega-3s have anti-inflammatory benefits and help prevent heart disease, whereas omega-6s lower blood cholesterol and support the skin.
Like all fats, EFAs provide energy. Their calorific value is similar to other fats and oils but, unlike saturated fats, they have important health roles. In fact, as their name suggest, they are essential and must be consumed regularly as the body has limited storage for them.


Both of the important EFA families - omega-6 and omega-3 - are components of nerve cells and cellular membranes. They are converted by the body into eicosanoids, leukotrienes and prostaglandins - all of which are needed on a second-by-second basis by most tissue activities in the body.

EFAs are involved in normal physiology, including:

Regulating pressure in the eye, joints, and blood vessels, and mediating immune response
Regulating bodily secretions and their viscosity
Dilating or constricting blood vessels
Regulating collateral circulation
Directing endocrine hormones to their target cells
Regulating smooth muscles and autonomic reflexes
Being primary constituents of cell membranes
Regulating the rate of cell division

Maintaining the fluidity and rigidity of cellular membranes

Regulating the inflow and outflow of substances to and from cells
Transporting oxygen from red blood cells to the tissues
Maintaining proper kidney function and fluid balance
Keeping saturated fats mobile in the blood stream
Preventing blood cells from clumping together (blood clots that can be a cause of heart attack and stroke).
Mediating the release of inflammatory substances from cells that may trigger allergic conditions.
Regulating nerve transmission and communication
If the diet is deficient in either omega-6 or omega-3 long-term degenerative illnesses will result.


However, because the end product (eg prostaglandin, leukotriene) of EFA metabolism differ slightly but significantly from omega-6 to omega-3, they must be present in balance for optimum health.
Both omega-6 and omega-3 fatty acids are essential but the body requires them in a ratio that is not normally achieved by the typical diet of today's industrialized nations.


Experts think that man evolved on a diet which would have had roughly 1-2 times more omega-6 than omega-3, though there is a school of thought which argues for a 1:1 ratio. (Currently, average UK intakes are in a ratio of around 8:1 in favour of the omega-6s, while in the US it is around 10:1 and in Australia nearer 12:1. Many individuals within those populations will have an even greater omega-6 to omega-3 imbalance).

Sources of Omega 3 Fats:

Cold water fish, tuna, cod liver, halibut, herring, mackerel, trout, salmon, sardines.
Sources of Omega 6 fats:
Sunflower seeds, seed oils, corn, pumpkin seeds, sesame seeds, nuts, meat, dairy products.
This article was written by Doug Lawrenson. Doug is a diet and nutrition expert and has trained several male and female athletes to British National level. If you would like to chat to Doug you can catch him on our muscle building forum. It's free to register, so come and join our growing community of muscle builders and fitness enthusiasts!

Benefits of Omega-3

Omega-3 fatty acids are polyunsaturated fatty acids composed of alpha-linolenic acid, eicosapentaenoic acid, or EPA, and docosahexaenoic acid, or DHA. They can benefit you whether you are healthy, at high risk for cardiovascular disease or have cardiovascular disease. Research reported by the American Heart Association (AHA) has shown that omega-3 fatty acids decrease your risk for arrhythmia. They also lower your triglyceride levels and slow your growth rate of atherosclerotic plaque. Omega-3 fatty acids can also slightly lower your blood pressure.

Food Sources of Omega-3

Foods rich in omega-3 fatty acids include albacore tuna, salmon, mackerel, herring, lake trout and sardines. The AHA recommends that you eat 7 oz. of these fatty fish per week. In order to benefit from the omega-3 fatty acids in the fish, you should bake or broil it rather than frying.

Omega-3 Supplements

If you have coronary artery disease or high triglycerides, you may benefit from fish oil or omega-3 supplements. Omega-3 fish oil supplements are usually made from the blubber of fatty fish. Two of the most important omega-3 fatty acids contained in fish oil are EPA and DHA. You should consult your doctor before taking fish oil supplements.


Food Sources of Omega-6
Omega-6 fatty acids are the most commonly consumed polyunsaturated fats in the American diet. There are two key dietary omega-6 fatty acids, one found in plants, called linoleic acid, and the other found in meats, called arachidonic acid. Fish has no omega-6 fatty acids. The top three omega-6 fats in the American diet are soybean oil, cottonseed oil and corn oil. These fats are in margarine, mayonnaise, salad dressings, snack foods, processed foods and fast foods. Consuming too many omega-6 fats may increase your risk of heart disease and may increase the growth of prostate tumor cells. (See References 1)

Omega-6 Supplements

Omega-6 fatty acids are available in supplemental oils that contain linoleic acid and gamma linolenic acid, such as evening primrose oil, oenothera biennis and black currant oils. Spirulina, often called blue-green algae, also contains gamma linolenic acid. Omega-6 supplements may be useful in treating eczema, breast tenderness, arthritis, diabetic neuropathy and psoriasis. You should consult your doctor before using any of these supplements because of the potential for side effects and interactions with medication.