OMEGA 3 FATTY ACIDS -- WHAT IS EPA AND DHA?
By Dr. Keith E. Lewis
May 9, 2008
Essential fatty acids are polyunsaturated oils. They are the good fats. They are essential because our body does not manufacture them, so they must be obtained through our diet on a daily basis for optimal health and well being. Essential fatty acids produce beneficial hormone-like compounds called the eicosanoids that affect the function of virtually every system and every cell in our body. The most important essential fatty acids are EPA and DHA which we will be discussing here. EPA and DHA are the Omega 3's and GLA (gamma linolenic acid) are Omega 6's. These are the good fats. These nutrients are responsible for cell flexibility, nerve function, mood support, and even weight control.
The importance of essential fatty acids
The body must receive a constant and balanced supply of essential fatty acids to ensure proper eicosanoid production. The eicosanoids are important because they regulate pain and swelling, so they have anti-inflammatory type mechanisms of action. They help maintain proper blood pressure, they help maintain proper cholesterol levels as we as triglyceride levels, and they provide fluidity in nerve transmission. Essential fatty acids are also recommended for many women during pregnancy and lactation and it is especially important for women to have good amounts of DHA because the baby is drawing upon her supply. DHA is critical for the healthy development of the brain, the eyes, and the nervous system.
So how do we get essential fatty acids in our diet? Where do they come from? The richest and most beneficial sources of essential fatty acids are found in cold-water fish, like salmon, sardines, mackerel, and herring. Borage and even primrose oils are also rich sources of gamma linolenic acid.
What is EPA?
Eicosapentaenoic acid (EPA) is a long chain of Omega 3 polyunsaturated essential fatty acid that is found in fish. Omega 3's are essential because humans are unable to synthesize them and therefore they must be obtained through our diet.
EPA, eicosanoids, and inflammation; so beyond the cardioprotective effects of Omega 3's, EPA is believed to be beneficial for many autoimmune and inflammatory disorders including arthritis, asthma, inflammatory bowel disease, systemic lupus erythematosus, and psoriasis. Omega 3 appears to be beneficial for cardiovascular health by reducing the risk of cardiac risk and ischemic stroke. In fact, the evidence is so strong that the American Heart Association has stated that people who have elevated triglycerides may need 2 to 4 grams of EPA and DHA per day provided as a supplement. There are also several psychotherapeutic mechanisms of action that occur in the presence of essential fatty acid. There are several studies that have shown and have linked low seafood intake to major depression, postpartum depression, and schizophrenia as well as to the severity of depressive symptoms. Although research in this area is somewhat limited, EPA has at this point at least shown to improve symptoms of schizophrenia and depression and increase remission time in bipolar disorder.
What is DHA?
Docosahexaenoic acid (DHA) is a long chain polyunsaturated Omega 3 essential fatty acid from fish. Again Omega 3's are essential because humans are unable to synthesis them, meaning they must obtain these through diet. The brain is particularly very rich in DHA where it increases membrane fluidity, and supports functions such as learning memory and cognitive development. DHA is very stress protective. One of the apparent benefits of DHA is to protect against the harmful effects of stress. Supplementation with DHA has been shown to reduce elevations and aggression and hostility in response to psychological stress. In addition, DHA may help to protect against the increased risk of heart attack associated with stress and depression. In clinical trials, low levels of DHA in the body and low fish consumption has been associated with increased risk factors associated with cognitive impairments, especially Alzheimer's disease. During pregnancy and lactation, proper nutrition with long chain Omega 3's appears to be especially important for the heath of both mother and the child. Inadequate maternal Omega 3 intake during pregnancy is a risk factor for premature birth, low birth weight, diabetes, and postpartum depression. DHA also appeared to be very important for infants and their visual and cognitive development. A recent study showed that children whose mothers had taken cod liver oil during pregnancy and lactation had higher IQs at age 4 than the mothers who had taken a placebo.