ESSENTIAL FATTY-ACIDS AND SKIN PROPERTIES

Skin structure of terrestrial animals and definition of essential fatty acids (EFA) are briefly reminded. Then, the lipid composition of normal epidermis (phospholipids, neutral lipids, sphingolilpids) and the levels of their major component EFAs (20:4n-6, arachidonic acid and principally 18:2n-6, linoleic acid) were indicated. From observations concerning EFA-deficient rats and recent data on the physiological role of epidermal lipids, we deduce the structural and biological fonctions of 20:4n-6, 18:2n-6 and of other dietary fatty acids, 18:3n-6 (gamma-linoleic acid) and 20:5n-3 (eicosapentaenoic acid). Shortly, the importance of these EFAs, 18:2n-6 notably, in the transepidermal water loss and keratinization is underlined.