INDICATORS OF LONG-CHAIN POLYUNSATURATED FATTY-ACID STATUS OF EXCLUSIVELY BREAST-FED INFANTS AT DELIVERY AND AFTER 20-22 DAYS

The fatty acid composition of plasma cholesterol esters (CE), erythroc ytes (RBC) and mature milk from seven lactating /women and their exclu sively breastfed newborns, living on Dominica, were studied. Blood sam ples were taken from umbilical cord and mother at birth. A sample of b reastmilk was collected on day 20-22 postpartum, together with a blood sample from the baby. At birth, cord blood plasma CE and RBC total lo ng chain polyunsaturated fatty acid (LC-PUFA) contents were higher, an d linoleic (18:2c,omega6) and alpha-linolenic (18:3c,omega3) acid cont ents lower, than in corresponding maternal compartments. Cord blood RB C LC-PUFA omega3 content was lower and LC-PUFA omega6 content higher t han in maternal RBC. After birth, feeding with human milk led to a dro p in LC-PUFA content in the plasma CE fraction, whereas RBC LC-PUFA co ntent remained virtually constant. Current understanding of the origin and relative affinity of fatty acids incorporated in plasma CE and RB C suggests that RBC LC-PUFA content is a more reliable parameter for L C-PUFA status than plasma CE LC-PUFA content. The RBC LC-PUFA data sug gest therefore that at birth the newborn has a lower LC-PUFA omega3 st atus than the mother, and that this does not change during three weeks of exclusive breastfeeding.