[Diet as a determinant of central nervous system development: role of essential fatty acids].

Nervous system is second to adipose tissue in containing the highest lipid concentration. Membrane phospholipids possess a high content of long chain polyunsaturated fatty acids (LCPUFA) of the n-3 and n-6 families, derived from the corresponding essential fatty acids. Docosahexaenoic acid (22:6n-3) is found in the highest concentrations in the gray matter and the photoreceptors of the retina. n-3 LCPUFA deficiency in infants, mainly if born preterm, modifies neural functions causing learning disabilities and visual function abnormalities. The adequate lipid nutrition of the mother before and during pregnancy and in breast feeding determine the lipid transfer of fatty acids to the fetus and infant, respectively. LCPUFA are conditionally essential in preterm infants, born with lower lipid depots. The formulation of infant formulas, mainly for preterm babies, should include adequate proportions of n-3 and n-6 LCPUFA.