Alpha-Linolenic Acid (ALA)

Alpha-linolenic acid (also known as α-linolenic acid or ALA) is a short-chain polyunsaturated omega-3 fatty acid found in many common vegetable and seed oils, such as rapeseed oil, hemp oil and flaxseed oil. It has the chemical name of all-cis-9,12,15-octadecatrienoic acid, with a formula C18H30O2 and a lipid name of 18:3 (n-3).

ALA is considered to be an essential fatty acid, as it cannot be produced by the body and so must be acquired through diet. Once obtained, it may be converted by the body into the long-chain fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). However, this conversion is not particularly efficient, with only 5-10% ALA being converted to EPA and only 0.01-5% to DHA.

Some studies have suggested that alpha-linolenic acid is related to a lower risk of cardiovascular disease and an improvement in retinal health, although the mechanism is still unclear. It is unknown whether this protective effect is provided by ALA itself, or by the docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) produced by the conversion of alpha-linolenic acid.