Polyunsaturated fatty acids in infant nutrition.

The availability of long-chain polyunsaturated fatty acids (LCP), such as arachidonic (C20:4n-6) and docosahexaenoic (C22:6n-3) acids, is important for early human growth and development. The capacity for endogenous synthesis of LCP from the precursor fatty acids linoleic (C18:2n-6) and alpha-linolenic (C18:3n-3) acid is limited in preterm and probably also in term infants. In utero, LCPs seem to be transferred preferentially from the mother to the foetus by the placenta. After birth, breast-fed infants receive preformed dietary LCP with human milk. In contrast, most current infant formulae are devoid of LCP. Premature infants fed such formulae develop rapid LCP depletion of plasma and tissue lipids, which is associated with reduced visual acuity during the first postnatal months. Therefore, LCP enrichment of formulae for premature infants is desirable. Recent observations indicate that term infants fed conventional formulae also exhibit lower plasma LCP values and may show functional disadvantages, but these data require further confirmation prior to drawing definite conclusions.