So what exactly are essential fatty acids and why are they essential?
Fatty acids are the building blocks of fats. These are acids produced when fats are broken down. They are considered "good fats." They are not highly soluble in water and can be used for energy in most types of cells .Fatty acids are found in oils and other fats that make up different foods. They are an important part of a healthy diet, because the body needs them for several purposes. One reason is to help move oxygen through the bloodstream to all parts of the body. They also aid cell membrane development, strength, and function, and they are necessary for strong organs and tissue
Some fatty acids are "essential" because we need them to live. We cannot manufacture our own, so we must ingest them through the foods we eat. The word "essential" is used as if to say "must be ingested". Other fatty acids are manufactured by the body, thus although we need them, they are not labeled as "essential".
The polyunsaturated fatty acids -- chemically speaking, those that are not "saturated" and thus have more than 1 double bond -- are divided into families depending on where their end-most double bond is located. There are two main subtypes of fatty acids: the omega-3 and omega-6 fatty acids. The Omega-3's are those with their endmost double bond 3 carbons from their methyl end. The Omega-6's are those with their endmost double bond 6 carbons from their methyl end.
Linoleic acid (omega-6) and alpha-linolenic acid (omega-3) are the only true "essential" fatty acids, because although a slow process, given enough alpha-linolenic acid, the body can synthesize eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) -- both important fatty acids of the omega-3 family. But, in order to effectively increase the body's stores, they must also be consumed.
So you might still be wondering why you need EFAs.
You need them to live. Many people are in a state of chronic low levels of essential fatty acids. EFA's are needed for maintaining proper cell membrane structure--which allows the proper distribution of nutrients throughout your body. They are needed for proper prostaglandin formation and maintenance, and most notably for the efficient metabolism of cholesterol. It has been repeatedly noted in population studies that people who consume more fish (omega-3's) consistently have a lower incidence of heart disease. Autopsies done on corpses have revealed a direct inverse correlation between the amount of omega-3's present and the healthiness of the heart. Those with low levels of omega-3's showed greater incidence of coronary heart disease than those with high levels of omega-3's and those with the highest levels of omega-3's had the lowest incidence of coronary heart disease.
So what are some good food sources for EFAs?
Food sources of linoleic acid (Omega-6) include seeds, nuts, grains and legumes. Alpha-linoleic acid(Omega-3) is found in the green leaves of plants, including phytoplankton and algae, and in some seeds, nuts and legumes (flax, canola, walnuts and soy) as well as in cold water fish. Flax seed above all is the highest best quality concentration of Omega-3 fatty acid. Some other Omega-3 fats can be found in foods such as salmon, mackerel, herring, walnuts, spinach, kidney beans, pinto beans and even broccoli, cauliflower and papaya. Omega-6 is most prominent in oils, fish, nuts and seeds.