Dietary fat is a concentrated source of energy for your body. It also helps your body absorb fat-soluble vitamins such as vitamin A and vitamin D. While some types of fats can be detrimental to your health, essential fatty acids are necessary in small amounts. You can obtain these polyunsaturated fats, specifically omega-3 and omega-6 fatty acids, in a variety of foods.
Fatty Acid Types
Fatty acids can be found free in your blood or as parts of larger molecules called triglycerides. Your body can oxidize fatty acids to provide energy. Many types of fatty acids exist, classified according to the types of bonds that link them together. Fatty acids that contain no double bonds are called saturated fats. These fats are present in animal fats and in some vegetable oils, such as palm kernel oils. Fatty acids that contain one or more double bonds are said to be mono- or polyunsaturated fats. Polyunsaturated fats are further classified according to the location of their double bonds.
Linoleic Acid
Linoleic acid is one type of polyunsaturated fatty acid. Also known as an omega-6 fatty acid, it is present in nuts, seeds and vegetable oils, including soybean and corn oils. Linoleic acid helps keep your cell membranes healthy. It is also important for healthy skin. In addition, linoleic acid serves as a precursor to a group of molecules called eicosanoids. These compounds, which include prostaglandins, help to moderate pain and inflammation. Linoleic acid is an essential fatty acid. Because your body is unable to synthesize it, you must obtain it in your diet.
Alpha-linolenic Acid
Alpha-linolenic acid, a type of omega-3 fatty acid, is the other essential fatty acid. Alpha-linolenic acid and other omega-3 fats are important for growth and development, and deficiency results in decreased vision and altered learning behaviors, including poor concentration and memory, according to the textbook "Biochemistry." Sources of alpha-linolenic acid include many vegetable oils, in addition to flaxseed, fatty fish and their oils. Smaller amounts of omega-3s can also be found in meat and eggs.
Recommended Amounts
A healthy diet includes adequate amounts of the essential fatty acids. The U.S. Department of Agriculture recommends that adult males get 17 g per day of linoleic acid, or omega-6. Males aged 50 and above should aim for 14 g per day. If you are a woman, strive to consume 11 or 12 g per day, 13 g if you are pregnant or lactating. Recommended amounts for omega-3 fats are much less. Men should consume 1.6 g per day. The USDA recommends 1.1 g of omega-3s per day for women. If you are pregnant or lactating, your target amounts are slightly higher.
Examples
Consuming adequate amounts of the essential fatty acids is easy if you follow a well-balanced diet. Two tbsp. of olive oil contains over 2.5 g of omega-6 fatty acids, or roughly 20 percent of the recommended amount for women. One oz. of almonds contains nearly 3.5 g. You can meet the recommendation for omega-3s by including fish, flaxseed or leafy green vegetables in your diet. One tbsp. of ground flaxseeds contains 1.8 g of omega-3s, which fulfills the daily requirement.
References
- "Biochemistry"; Pamela C. Champe; 2005
- Institute of Medicine: Dietary Reference Intakes: Macronutrients
- "The Nutrition Doctor's A-To-Z Food Counter"; Dr. Ed Blonz; 1999
Member Comments