- EPA and its metabolites act in the body largely by their interactions with the metabolites of arachidonic acid; see Essential fatty acid interactions for detail.
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|Molar mass||302.451 g/mol|
|Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)|
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Eicosapentaenoic acid (EPA or also icosapentaenoic acid) is an omega-3 fatty acid. In physiological literature, it is given the name 20:5(n-3). It also has the trivial name timnodonic acid. In chemical structure, EPA is a carboxylic acid with a 20-carbon chain and five cis double bonds; the first double bond is located at the third carbon from the omega end.
It is obtained in the human diet by eating oily fish or fish oil, e.g. cod liver, herring, mackerel, salmon, menhaden and sardine, and various types of edible seaweed phytoplankton. It is also found in human breast milk.
However, fish do not naturally produce EPA, but obtain it from the algae they consume. It is available to humans from some non-animal sources (e.g. commercially, from microalgae). Microalgae are being developed as a commercial source. EPA is not usually found in higher plants, but it has been reported in trace amounts in purslane. In 2013, it was reported that a genetically modified form of the plant Camelina produced significant amounts EPA.
The human body converts alpha-linolenic acid (ALA) to EPA. ALA is itself an essential fatty acid, an appropriate supply of which must be ensured. The efficiency of the conversion of ALA to EPA, however, is much lower than the absorption of EPA from food containing it. Because EPA is also a precursor to docosahexaenoic acid (DHA), ensuring a sufficient level of EPA on a diet containing neither EPA nor DHA is harder both because of the extra metabolic work required to synthesize EPA and because of the use of EPA to metabolize into DHA. Medical conditions like diabetes or certain allergies may significantly limit the human body's capacity for metabolization of EPA from ALA.
The US National Institute of Health's MedlinePlus lists medical conditions for which EPA (alone or in concert with other ω-3 sources) is known or thought to be an effective treatment. Most of these involve its ability to lower inflammation.
Studies have suggested that EPA may be efficacious in treating depression. A 2009 meta analysis found that people taking omega-3 supplements with a higher EPA:DHA ratio experienced fewer depressive symptoms.
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