The term "fatty" refers to the fact that omega-3 fatty acids are naturally broken down from fats, like fish oil in the case of EPA and DHA (two of the most important Omega 3 Fatty acids). Omega-3 fatty acids are believed to be essential fatty acids as your body needs them to survive, yet the body does not make them. Thus, a daily supplement of EPA and DHA should to be taken to ensure your body has enough EPA and DHA.
Specific anti-inflammatory hormones, 'Eicosenoids', come from EPA. These properties make EPA beneficial in the prevention of cardiovascular ailments, the maintenance of healthy joints and the prevention of various forms of joint problems. This is because free radicals cause damage to these cells activating an inflammatory response. By hindering the inflammatory response, EPA principally, helps maintain the health of the heart, brain and joints.
DHA is more easily absorbed in the body and used in greater amounts than EPA. Good brain function is dependent upon adequate amounts of DHA, which makes up 40% of the fatty acids in the membranes of brain cells.
Brain function may be omega-3's most vital and essential structural benefit. The cell membrane of neurons is 20% omega-3 fatty acids. As electrical signals jump from one neuron to another, they must first pass through these cell membranes. DHA is thought to make the membranes more elastic, allowing a channel to change shape and open up within them. Only DHA is flexible enough to completely perform this function.
The brain depends on DHA and EPA to create and modify neural structures. This adaptive nature of the brain is known as "plasticity". A deficiency of DHA or EPA acids reduces the adaptability of the brain. It is believed that reduced plasticity may be one significant factor in the development of depression.