Evolution of lipid composition of human milk.

02 September 2010

A team of Spanish researchers focused on the evolution of lipid composition of human milk in women delivering very preterm (before 30 weeks of gestation; n = 10), preterm (between 30 and 37 weeks; n = 10), and term infants (between 38 and 42 weeks; n = 23).

They observed that lipid content of human milk was significantly higher for very preterm infants than for others. Moreover, at the beginning of the period of lactation (colostrum and transitional milk), they noticed that medium-chain saturated fatty acid proportions in milk were significantly higher in very preterm cases (p < 0.05) and that these proportions decreased with the age of gestation. Besides, during lactation, medium-chain saturated fatty acids, alpha-linolenic acid, and rumenic acid proportions increased (p < 0.05) whereas those of most long-chain saturated fatty acids and most long-chain polyunsaturated fatty acids from the n-3 and n-6 families decreased (p < 0.05).

These variations of lipid composition in human milk (during lactation and depending on the age of gestation) are very likely to be due to a natural adaptation to the newborn’s needs. It would therefore be wise to take this observation into account when feeding newborns banked human milk and when designing infant formulas.