Two polyunsaturated fatty acids cannot be made in the body and are therefore dietary essentials: linoleic (C18:2 ω6) and α‐linolenic (C18:3 ω3). Several other fatty acids have some EFA activity in that they cure some, but not all, of the signs of (experimental) deficiency. Arachidonic, eicosapentaenoic (EPA), and docosahexaenoic (DHA) acids are physiologically important, although they are not dietary essentials since they can be formed from linoleic and α‐linolenic acids.
The requirement to prevent deficiency is about 1% of total energy intake, equivalent to 260 mg/MJ; a desirable intake, and the basis of reference intakes, is 8–10% of energy intake, about 2–2.6 g/MJ. Although all fatty foods contain some essential fatty acids, the richest sources are vegetable and fish oils.
Subjects: Medicine and Health.