Doctors and dieticians encourage you to eat a low-fat diet to reduce your risk for heart disease, diabetes and other chronic illnesses. You must realize that in addition to reducing the amount of fat in your diet you need to consume the right type of fat because some fat contains essential fatty acids. The human body needs two types of fatty acids: omega-3 fatty acids, which includes three essential fatty acids, and omega-6 fatty acids, which also includes three fatty acids.
Omega-3 Fatty Acids
Fats classified as polyunsaturated contain omega-3 fatty acids. These essential fatty acids play a vital role in brain function, support normal growth and development and may reduce inflammation. The three fatty acids classified as omega-3 include alpha-linolenic acid -- ALA, eicosapentaenoic acid -- EPA, and docosahexaenoic acid -- DHA. The human body cannot internally produce ALA, making it essential in the diet, but can produce EPA and DHA from ALA. The conversion of ALA to EPA and DHA may not produce amounts sufficient to meet the needs of the body, making these two fatty acids "conditionally essential." A heart-healthy diet should balance the consumption of omega-3 fatty acids and omega-6 fatty acids, according to the University of Maryland Medical Center.
Omega-6 Fatty Acids
Omega-6 fatty acids, also found in polyunsaturated fats, perform functions similar to the omega-3 fatty acids such as supporting brain function, growth and development. A difference arises in the fact that omega-3 fatty acids reduce inflammation while omega-6 fatty acids seem to promote inflammation. A person eating the typical American diet consumes between 14 and 25 times more omega-6 fatty acids than omega-3 fatty acids, according to the University of Maryland Medical Center. The body can convert the essential omega-6 fatty acids, linoleic acid, or LA, to another omega-6 fatty acid, gamma-linolenic acid -- GLA. The body breaks down GLA further into arachidonic acid, referred to as AA.
Food Sources
Although the body can produce some of these fatty acids, food sources of each are an important part of a balanced diet. The oils of plants and nuts, such as flaxseed oil, soybean oil, pumpkin seed oil and walnuts with walnut oil contain omega-3 fatty acids. The best source for omega-3 is fatty fish, including salmon, mackerel, tuna, halibut and herring. Fish oils contain all three essential omega-3 fatty acids. The best food sources of omega-6 fatty acids include soybean, safflower and corn oils as well as nuts, seeds and some vegetables. Since only animals produce AA, this omega-6 fatty acid occurs in foods derived from animals like meat, poultry and eggs.
Amounts
A diet rich in omega-3 fatty acids may help reduce the risk of heart disease, according to the American Heart Association. Consuming omega-3 fatty acids can help decrease triglyceride levels -- another type of fat known to contribute to heart disease -- slow the growth rate of plaques and reduce blood pressure. Taking supplemental oils that contain omega-6 fatty acids, like evening primrose oil, may help to reduce symptoms of eczema and attention deficit disorder and slow the progression of osteoporosis, according to the University of Maryland Medical Center. The Institute of Medicine recommends adult males between the ages of 19 and 50 consume 17 g of omega-6 fatty acids per day while women in the same age-group need to consume 12 g per day. Adult males over the age of 19 should incorporate 1.6 g of omega-3 fatty acids per day while females need only 1.1 g per day.
References
- University of Maryland Medical Center: Omega-3 Fatty Acids; Stephen Ehrlich; June 2009
- Physicians Committee for Responsible Medicine: Essential Fatty Acids; May 2006
- Linus Pauling Institute: Essential Fatty Acids; Victoria Drake; April 2009
- University of Maryland Medical Center: Omega-6 Fatty Acids; Stephen Ehrlich; June 2009
- Institute of Medicine: Dietary Reference Intakes -- Macronutrients; 2005
- American Heart Association: Fish and Omega-3 Fatty Acids; September 2010
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