EPA is an abbreviation for eicosapentaenoic acid, one of the long-chain omega-3 fatty acids. Its structure includes twenty carbon atoms and five double bonds. Learning about such acids has been an important part of research into the fat composition of marine organisms and their place in the diet.
Characteristics and context
EPA sources include, but are not limited to, certain fish oils and microalgae. It is not the same compound as DHA or plant ALA, although they belong to the same family. The supplement must distinguish between the weight of the oil, the total amount of omega-3 and the separately declared amount of EPA. A large number of milligrams of oil on the front of the packaging does not mean the same content of this acid. When comparing products, what matters is the amount in the recommended portion and the exact composition of the fat material.
Meaning and application
C20:5n-3 is a shortened way of presenting the structure of EPA. The numbers refer to chain length, number of double bonds and omega-3 family membership. They do not provide the content of a specific raw material. This is an example of structural information that should be distinguished from a nutrition declaration. The name of the acid and the weight of the oil in the capsule answer different questions, even if they are placed next to each other.
In practice
On the packaging, it is worth looking for the amount of EPA per serving and separate information about DHA, if it is present. The sum of these fatty acids does not have to equal the total weight of fat or the sum of all omega-3s. Oil from a specific source may have a different profile depending on the material and preparation. A fair comparison therefore takes into account specific values, recommended use and storage conditions. A general statement of marine origin does not replace more precise product specifications.