By now, it is widely known that omega 3 polyunsaturated fats are necessary components of our daily diets. They have anti-inflammatory properties that lead to good cardiovascular health, lower the risk or certain forms of cancers, diabetes and auto-immune diseases. They are also essential for development and function of the brain and nervous system and are believed to be helpful for warding off disorders such as depression, PMS, ADHD, Parkinson’s and Alzheimer’s Disease (AD). There are three fatty acids that fall into the category of omega 3:
Alpha (a) linoleic oil (ALA) - this fatty acid is considered essential because it cannot be manufactured by the body. Good sources include flax, hempseed, avocado, walnut and canola oils.
Docoshexaenoic acid (DHA) and Eicosapentaenoic acid (EPA) are produced from ALA, however, it has been reported that this process is often inefficient. In fact, the high prevelance of omega 6 fats in our diets that include corn, soy, cottonseed and sunflower oils actually block the conversion of ALA to DHA. And omega 6 fats are generally pro- inflammatory, suggesting that the unhealthy balance of omega 6 to omega 3 plays a role in many diseases. So to correct that balance and to ensure that you have enough EPA and DHA, you must include them into your diet. The best source for both fatty acids is oily fish such as salmon, tuna, mackerel and sardines. Marine algae are also reported as excellent sources of DHA and possibly EPA. In addition, I just purchased organic, DHA- and EPA-containing eggs.
ALA is a medium-chain fatty acid (it has a "tail" that is 18 carbons long) and DHA and EPA are long-chain fatty acids (22 and 20 carbon, respectively). DHA is the most biologically active of the omega 3s. Both DHA and EPA are necessary for heart health and both, but specifically, DHA is required for brain, central nervous system, and retinal development and function. DHA is also required for the formation and repair of the large, fatty membrane myelin sheath that insulates and signals along the length of neurons. The American Dietetic Association recommends at least 500 mg/day combined of DHA and EPA. This is equivalent to 2 servings of fatty fish/week. However, the Japanese diet can contain up to three times these levels per day and has been implicated in much lower rates of heart disease. Higher doses (~2200 mg/day) of DHA have also been shown to lower triglyceride levels and 1700 mg/day of DHA in fish oil supplements has been associated with a reduction in inflammation in the brains of AD patients. Studies with DHA in mouse models of AD have also demonstrated improvements in the pathological effects of AD including oxidative damage, inflammation, defective signaling between neurons and decreased cognitive function.
Because DHA and EPA are crucial for keeping our cardiovascular and nervous systems healthy, they must be a regular part of our diet. However, if you’re consuming little or no fish either because you are a vegan or vegetarian, or because of concerns about mercury, then it has been strongly suggested that you take fish oil or algal oil supplements that specifically contain DHA and EPA. Plant sources such as flaxseed oil will only supply ALA. In addition, David Wolfe in his book Superfoods suggests adding blue-green algae, chlorella or spirulina to the diet because the phospholipids supplied by eating one of these sources of marine organism together with fish oil will increase the absorption and delivery of DHA and EPA to the brain. Even on their own, he claims that these algae already contain all the phospholipids and essential fatty acids required by the body.
Whichever way you decide to do it, if you want to stay healthy, active, and alert, make ALL three omega 3s a regular part of your diet.