Omega-3 Fatty Acids Info

Omega-3 fatty acids are a family of polyunsaturated fatty acids. Note that spoken-word and visual media have by and large adopted the technically-incorrect pronunciation of "Omega 3", as opposed to the term used by chemists, "Omega minus 3.") Important omega-3 fatty acids in nutrition are: a-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). The human body cannot synthesize omega-3 fatty acids de novo, but can synthesize all the other necessary omega-3 fatty acids from the simpler omega-3 fatty acid a-linolenic acid. Therefore, a-linolenic acid is an essential nutrient which must be obtained from food, and the other omega-3 fatty acids which can be either synthesized from it within the body or obtained from food are sometimes also referred to as essential nutrients.

Omega-3 fatty acids which are important in human nutrition are: a-linolenic acid (18:3, ALA), eicosapentaenoic acid (20:5, EPA), and docosahexaenoic acid (22:6, DHA). These three polyunsaturates have either 3, 5 or 6 double bonds in a carbon chain of 18, 20 or 22 carbon atoms, respectively. All double bonds are in the cis-configuration, i.e. the two hydrogen atoms are on the same side of the double bond.

The most widely available source of EPA and DHA is cold water oily fish such as wild salmon, herring, mackerel, anchovies and sardines. The oil from these fish have a profile of around seven times as much omega-3 as omega-6. Farmed salmon, being grain fed, have a higher proportion of omega-6 than wild salmon. Other oily fish such as tuna also contain omega-3 in somewhat lesser amounts. Some supplement manufacturers remove heavy metals and other contaminants from the oil through various means, such as molecular distillation, which increases purity, potency and safety. Although fish is a dietary source of omega-3 fatty acids, fish do not synthesize them; they obtain them from the algae in their diet. For this reason, there is often a significant difference in EPA and DHA concentrations in farmed vs wild caught fish.