n-3 fatty acid requirements of the newborn.
Whether docosahexaenoic acid (22:6n-3) is an essential nutrient for term or preterm infants, or if not, the quantity of dietary linolenic acid (18:3n-3) needed to support sufficient synthesis of 22:6n-3 for assimilation in the central nervous system is unknown. Infants fed formulas have lower plasma and red blood cell (RBC) levels of 22:6n-3 than breast fed infants. No relationship between the intake of 18:3n-3 in formula (0.8 or 4.5% of fatty acids, 18:2n-6/18:3n-3 ratio 35:1 or 7:1, respectively) and the infant's RBC 22:6n-3 was found. Premature infants (< 33 wk gestation) also showed a decrease in RBC 22:6n-3 during feeding with formula containing 18:3n-3 as the only n-3 fatty acid. However, a marked decrease in plasma and RBC 22:6n-3 occurred between premature birth and the start of full enteral feeding at 1-2 wk of age. This was not reversed by breast milk or formula feeding. Piglets, which are appropriate for studies of infant lipid metabolism, had decreased brain synaptic plasma membrane, retina and liver 22:6n-3 and increased 22:5n-6 when fed formula with 0.8% fatty acids (0.3% of kcal) as 18:3n-3. Formula with 4.0% fatty acids (1.7% of kcal) as 18:3n-3 resulted in similar accretion of 22:6n-3 in the organs compared to milk fed animals. The studies suggest the dietary requirement for 18:3n-3 in term animals in energy balance exceeds 0.3% diet kcal.(ABSTRACT TRUNCATED AT 250 WORDS)
Innis
S M
SM
Department of Paediatrics, University of British Columbia, Vancouver, Canada.
D000818:Animals; D004281:Docosahexaenoic Acids / Q000097:blood / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage*; D005865:Gestational Age; D006801:Humans; D007223:Infant; D007225:Infant Food; D007227:Infant Nutritional Physiological Phenomena; D007231:Infant, Newborn; D007234:Infant, Premature / Q000097:blood; D008042:Linolenic Acids / Q000008:administration & dosage; D008895:Milk, Human; D009751:Nutritional Requirements; D010288:Parenteral Nutrition; D013552:Swine
D015525:Fatty Acids, Omega-3; D008042:Linolenic Acids; D004281:Docosahexaenoic Acids