Some polyunsaturated fats are essential, which means that they are necessary for life and that the body cannot make them on its own. We must therefore get these fatty acids through the diet. The two polyunsaturated fatty acids that are essential are called alpha-linolenic acid and linoleic acid. Alpha-linolenic acid is an omega-3 fatty acid, and linoleic acid is an omega-6 fatty acid. Omega-3 and omega-6 are actually collective names for two families of polyunsaturated fatty acids, with similar chemical structure. Omega-3 and omega-6 are the most important polyunsaturated fatty acids, but there are also other beneficial polyunsaturated fatty acids such as omega-9. In this category you will find food supplements that contain polyunsaturated fats such as omega-3 and omega-6. Alpha-linolenic acid and linoleic acid are medium-chain fatty acids, which to some extent are converted in the body to the long-chain fatty acids docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and arachidonic acid. DHA and EPA are omega-3 fatty acids, while arachidonic acid is an omega-6 fatty acid. The long omega-3 fatty acids EPA and DHA are mainly found in fatty fish, but a vegetable source of them is algae oil. The polyunsaturated fats have many important functions in the body. They are used, among other things, to build and repair cells and regulate blood pressure. They also affect the immune system and kidney function. Replacing saturated fat with polyunsaturated fats can also contribute to a reduced risk of cardiovascular disease. DHA contributes to: to maintain normal brain function to maintain normal vision to maintain normal blood triglyceride levels EPA and DHA contribute to: to maintain a normal blood pressure contributes to maintaining normal triglyceride levels in the blood contributes to the normal functioning of the heart Polyunsaturated fatty acids for children: Essential fatty acids are needed for normal growth and development in children. Maternal intake of DHA contributes to normal brain development in the fetus and in breastfed infants. DHA intake contributes to normal vision development in infants up to 12 months. Maternal intake of DHA contributes to normal development of the eye in fetuses and breastfed infants.