Supply and metabolism of LCPUFA in term infants

Abstract

Long-chain polyunsaturated fatty acids with 20 and 22 carbon atoms (LCPUFA) are essential for early human growth and development (1). The available evidence strongly suggests that a dietary supply of LCPUFA is desirable for preterm infants (2). The capacity for endogenous synthesis of these long-chain metabolites seems limited in low birth weight infants, and the feeding of preterm infants with formulas devoid of LCPUFA results in rapid LCPUFA depletion of plasma and tissue lipids (3,4), which has been associated with reduced visual acuity during the first postnatal months and with altered Bayley mental developmental index scores at one year of age (see Chapter 15 by Dr Carlson, this volume). The degree to which a dietary source of preformed LCPUFA is also essential for term infants is an area of active investigation. As in preterm infants, levels of docosahexaenoic acid (DHA; 22:6 n-3) in plasma and red blood cell (RBC) phospholipids of term, formula-fed infants are lower than those of breast-fed infants. Controversy exists over whether the absence of AA from the diet affects plasma and erythrocyte arachidonic acid (AA; 20:4 n-6) levels in term infants. Some studies report that AA levels in plasma and RBC are very stable, while others report decreased levels in infants not receiving dietary AA (reviewed in Ref. 5).