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.
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.
By Neale Cranwell