EPA DHA Essential Fatty Acids

EPA and DHA for Health

DHA and EPA
Docosahexaenoic acid (DHA) is an omega-3 fatty acid that is essential for the proper functioning of our brains as adults, and for the development of our nervous system and visual abilities during the first six months of life. Lack of sufficient DHA may be associated with impaired mental and visual functioning as well as attention-deficit hyperactivity disorder (ADHD) in children. Low levels have also been associated with depression and Alzheimer's disease in adults. Our bodies naturally produce some DHA, but in amounts too small and irregular to ensure proper biochemical functioning. Therefore, preformed DHA must be consumed in the diet through foods such as cold water fatty fish or in supplement form in order to assure an adequate supply.

Eicosapentaenoic acid (EPA) is one of several omega-3 fatty acids used by the body. The typical Western diet is relatively deficient in omega-3 fatty acids compared to the diets of our ancestors. Our main dietary sources of EPA are cold water fish such as wild salmon. Fish oil supplements may also raise the concentrations of EPA in the body. Increased intake of EPA has been shown to be beneficial in coronary heart disease, high blood pressure, and inflammatory disorders such as rheumatoid arthritis.

Since studies on the health of Greenland Eskimos in the 1970s, both DHA and EPA have been purported to have many health benefits when included in ones diet on a regular basis. The Eskimos eat large amounts of DHA and EPA in their diets. As all natural fish and fish oils contain both substances, learning which of them are the major contributors to the health benefits claimed for fish or fish oil has been hard, or if both are needed to produce these benefits. Epidemiological evidence suggest that populations consuming marine diets rich in the omega-3 eicosapentaenoic acid (EPA) have a low incidence of cancer. A potential anti-cancer activity of EPA is further supported by in vitro and in vivo experimental studies.

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.

There is now also good evidence that EPA and DHA found in fish oils may protect against CHD. In Japan, the incidence of CHD and cerebral thrombosis have been found to be inversely proportional to blood levels of EPA. These levels are generally ten times as high among Japanese as among Americans. Both West and East Germany and Czechoslovakia now include linoleic acid or essential fatty acids in their tables of RDA; the recommended daily intake is about 10 grams.

Thrombotic disorders are currently treated and prevented by utilising pharmacological concentrations of eicosapentaenoic acid (EPA; C20:5w 3). Controversy and disagreement about the beneficial effects of this essential fatty acid are legion. EPA has been shown to lower, elevate or have no effect on cholesterol metabolism. Supplementation of EPA to different diets may be the reason for the inconsistency of effects.

Dietary polyunsaturated fatty acids have been reported as a potential group of natural products which modulate tumor cell growth. In present study, EPA was found to inhibit proliferation of human leukemic HL-60 and K-562 cells in vitro.

In this study, we investigated the hypolipidemic action of EPA and its mechanism. Three types of 5% fat diets (stearic acid, linoleic acid, and EPA) were prepared in our laboratory. Rats that weighed 170-190 g were fed one of these diets for 20 weeks at an equivalent calorie value (groups S, L, and E). Weight gain occurred in the following order: group E < group S < group L. Serum levels of total cholesterol, triglycerides, phospholipids and total lipids were significantly lower in group E than in the other groups. Analysis of the fatty acid composition of adipose tissue showed that the level of C18:1 was significantly higher in group S, that of C18:2 was significantly higher in group L, and that of C16:0 was significantly higher in group E than in the other groups. These results indicated that EPA had a hypolipidemic action, higher ketogenicity, and lower lipogenicity than the other fatty acids. Inclusion of EPA in the diet of hyperlipidemic subjects may thus help in the primary prevention of hyperlipidemia and, in turn, morbid obesity.

Epidemiological studies suggest that a diet high in marine fatty acids (fish oil) may have beneficial effects on inflammatory conditions such as rheumatoid arthritis and possibly asthma...The single study performed in children also combined dietary manipulation with fish oil supplementation and showed improved peak flow and reduced asthma medication use. There were no adverse events associated with fish oil supplements.

There is little evidence to recommend that people with asthma supplement or modify their dietary intake of marine omega-3 fatty acids (fish oil) in order to improve their asthma control. Equally, there is no evidence that they are at risk if they do so.

Omega-3 fatty acids have been shown to modify several key risk factors for cardiovascular disease. However, it is not clear whether the apparent protection against cardiovascular disease is directly related to antiatherogenic functions of these fatty acids or is mediated through their modification of the risk factors through mechanisms not directly related to lipids. A major question concerns the importance of lipid modification, which is a potent outcome of fish-oil supplementation. On balance, lipid modification is likely to represent a significant antiatherogenic factor. The benefits include increased HDL2-cholesterol concentrations, reduced triacylglycerol-rich lipoprotein concentrations, reduced postprandial lipemia, and reduced remnant concentrations. In contrast, LDL-cholesterol concentrations have often been noted to rise and the potential of increased oxidizability of LDLs is potentially adverse with lipid modification, but this potential can be overcome with vitamin E supplementation. The characteristic lipid changes and the underlying mechanisms are reviewed. Additional benefits of fish oils include improved endothelial function and better arterial compliance (elasticity). Future trials will be needed to determine minimum effective dosages of eicosapentaenoic and docosahexaenoic acids over lengthy periods and to show cardiovascular disease reduction through intervention.

It has been postulated that patients with ulcerative colitis (UC) have altered reactivity of gut-associated lymphoid tissue. In such cases there is intense infiltration of the mucosa with immune competent cells and associated tissue damage. We have shown previously that the dietary supplementation with the omega-3 polyunsaturated fatty acids, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) results in significant systemic immune suppression. The aim of this study, therefore, was to evaluate the in situ effect of omega-3 polyunsaturated fatty acids on distal proctocolitis...In patients receiving omega-3 polyunsaturated fatty acids supplementation, there was improvement in the disease activity and histological scores, compared with pretreatment evaluation. This study has demonstrated both evidence of suppression of in situ immune reactivity and concurrent reduction in disease activity in patients with proctocolitis receiving omega-3 polyunsaturated fatty acids supplementation. This may have important implication for therapy in patients with ulcerative colitis.

Limited evidence gives support to an hypothesis suggesting that the symptoms of schizophrenia may result from altered neuronal membrane structure and metabolism. The latter are dependent on blood plasma levels of certain essential fatty acids (EFAs) and their metabolites. Several studies have shown those with schizophrenia often have low levels of the particular EFAs necessary for normal nerve cell membrane metabolism... Early results from a few trials suggest a positive effect of eicosapentaenoic acid (EPA) over placebo for scale-derived mental state outcomes. The data, however, is limited making these results difficult to analyse and interpret with confidence. A single small study (n=30) investigated the value of using EPA as sole treatment for people hospitalised for relapse. Results suggest that EPA may help one third of people avoid instigation of standard antipsychotic drugs for 12 weeks (RR 0.6, CI 0.4-0.91). REVIEWER'S CONCLUSIONS: All data are preliminary, but results look encouraging for fish oil. EPA does not seem harmful, may be acceptable to people with schizophrenia and have moderately positive effect. A further trial is soon to be reported from the USA and more are underway or planned in the South Africa and Norway. Considering that EPA may be an acceptable intervention, large, long simple studies reporting clincially meaningful data should be anticipated.

The administration of the omega-3 fatty acid eicosapentaenoic acid (EPA) to a drug-naive patient with schizophrenia, untreated with conventional antipsychotic medication, led to a dramatic and sustained clinical improvement in both positive and negative symptoms. This was accompanied by a correction in erythrocyte membranes of abnormalities in both omega-3 and omaga-6 highly unsaturated fatty acids. Therefore EPA is able to reverse the phospholipid abnormalities previously described in schizophrenia. This reversal is associated with, and is likely to be the cause of, the clinical improvement. In particular, EPA appears to have reversed the depletion of not only omega-3 highly unsaturated fatty acids, but also of membrane arachidonic acid, possibly via inhibition of highly unsaturated fatty acid-specific phospholipase A(2), an enzyme which removes highly unsaturated fatty acids from the S(N)2 position of membrane phospholipids, or by activation of a fatty acid coenzyme A ligase. Correction by EPA of abnormalities in both enzyme systems is not ruled out.

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