Omega-3 and Omega-6 Fatty acids

Fatty acids are organic compounds composed of carbon chains of varying lengths, with an acid group on one end and hydrogen bound to all the carbons of the chain. Essential fatty acids (EFAs) are those that are necessary for health, but cannot be synthesized by the body. Therefore, it is important to supply the body with EFAs through one's daily dietary intake. EFAs are also called vitamin F or polyunsaturates. They are important ingredients for the growth and maintenance of cells. The body utilizes essential fatty acids for hormone production, specifically for the production of prostaglandins , which aid in reducing hypertension , migraine headaches, and arthritis .

Essential fatty acids offer many positive effects for the body, including the nourishment of skin and hair; reduction of blood pressure , cholesterol , and triglyceride levels; prevention of arthritis and inflammation; and the reduction of the risk of blood clotting . Furthermore, essential fatty acids help protect the body from cardiovascular disease, candidiasis , eczema , and psoriasis , and they play a critical role in brain development and in the transmission of nerve impulses.

Types of EFAs

There are basically two types of essential fatty acids, omega-3 fatty acids, also known as linolenic acids, and omega-6 fatty acids, which are also called linoleic acids. The two types are distinguished by their chemical structures. Omega-3 EFAs are found in deepwater fish, fish oil, and some vegetable oils, such as canola, flaxseed, and walnut oil. Nuts are also a good source of omega-3 fatty acids, particularly hazelnuts, almonds, pecans, cashews, walnuts, and macadamia nuts. The best fish oil sources are salmon, mackerel, anchovies, sardines, and herring, which have a high fat content and provide more omega-3 than other fish. Flaxseeds are also a good source, and they are low in saturated fats and calories and have no cholesterol. Omega-6 fatty acids are found in raw nuts, seeds, legumes , and in unsaturated vegetable oils, such as borage oil, grape seed oil, primrose oil, sesame oil, and soybean oil.

Benefits of EFAs

There are many health benefits attributable to essential fatty acids. Research has shown that diets rich in monounsaturated fatty acids, which contain the omega-3 variety, reduce total mortality by 70 percent in patients who have

already experienced a heart attack . This has led to a general recommendation to consume at least one meal a week of fish rich in omega-3 fatty acids. It is generally accepted that omega-3 fatty acids help to reduce the levels of triglycerides in the body, thus decreasing the risk of heart disease .

Omega-6 fatty acids have been shown to be beneficial in the reduction of cholesterol levels when they are substituted for saturated fats in a person's diet . The benefit in consuming omega-6 fatty acids therefore lies in the fact that they reduce the incidence of coronary artery disease, which is a condition where excess cholesterol builds up on the arteries of the heart, eventually blocking the flow of blood and causing a heart attack.

SEE ALSO Fats ; Heart Disease ; Lipid Profile .

Susan S. Kim Jeffrey Radecki

Bibliography

Masley, Steven C. (1998). "Dietary Therapy for Preventing and Treating Coronary Artery Disease." American Family Physician 57:1299–1305. Also available from <http://www.aafp.org>

Sizer, Frances, and Whitney, Eleanor (2000). Nutrition: Concepts and Controversies, 8th edition. Stamford CT: Wadsworth/Thomson Learning.