Eicosapentaenoic acid and decosahexaenoic acid are omega-3 long-chain (C18), unsaturated fatty acids found in fish oils. EPA/DHA, which are usually found together, are exciting fatty acid nutrients that have become very popular recently in the literature and as supplements. Like GLA, EPA/DHA also seem to affect the synthesis of the prostaglandins series 1, but even more the series 3, and this may give them additional anti-inflammatory benefits. However, their main effect is to help lower blood fat levels.
The intake of dietary EPA/DHA is enhanced by eating coldwater fish regularly, such as salmon, herring, mackerel, or sardines that feed on certain plankton, or by taking additional oil supplements. Increased intake of EPA/DHA has been shown in numerous studies to lower blood triglyceride and cholesterol levels, while raising the level of high-density lipoprotein (HDL), the “good” cholesterol.
These lipid-lowering effects, along with some benefits in reducing platelet aggregation and clotting potential, make the use of EPA/DHA very important in the treatment or prevention of cardiovascular disease or in anyone with high blood fats or low HDL. The decreased blood viscosity and lower fat levels help reduce the risk of heart attacks. The mild anti-inflammatory effects, possibly a result of increased PGE1 and PGE3 prostaglandins, may also be helpful and has suggested the possible use of EPA/DHA in arthritis and other inflammatory conditions. In rheumatoid arthritis, for example, EPA/DHA supplementation has been shown to reduce joint stiffness and soreness and to improve flexibility.
|Lupus and other outoimmune diseases|
There are no significant side effects from the use of EPA/DHA, except for mild nausea from taking oils that some people experience. Fish oils contain no vitamin C or E and are more likely to oxidize and go rancid. Therefore, many of the commercial preparations have vitamin E added to prevent oxidation. Fish liver oils are not recommended, even though they contain some EPA and DHA, because they are too high in vitamins A and D, and because livers tend to concentrate any toxic materials the fish (or any animal) have absorbed.
In general, as a preventive for cardiovascular disease, it is recommended that we eat a portion of the oily fishes two or three times weekly. If we do have high blood fats, low HDL, or increased risk of cardiovascular disease, we can supplement 500 mg. of EPA/DHA twice daily to improve these conditions, though in my experience, it does not work that well to lower cholesterol. (Higher amounts may be needed for this effect.) Simple, moderate exercise works better, and as for nutritional supplements, it seems that other agents such as niacin or L-carnitine may be better at lowering lipids. Also, for supplying the valuable omega-3 fatty acids, cold-pressed flaxseed oil is a better and less expensive source.