Blood lipid docosahexaenoic and arachidonic acid in term gestation infants fed formulas with high docosahexaenoic acid, low eicosapentaenoic acid fish oil.

The effect of fish oil high in docosahexaenoic acid (22:6n-3) and low in eicosapentaenoic acid (20:5n-3) in formula on blood lipids and growth of full-term infants was studied. Infants were fed formula with about 15% oleic acid (18:1), 32% linoleic acid (18:2n-6), 4.9% linolenic acid (18:3n-3) and 0, 0.10, or 0.22% 22:6n-3, or 35% 18:1, 20% 18:2n-6, 2.1% 18:3n-3 and 0, 0.11, or 0.24% 22:6n-3 from 3 d to 16 wk of age (n = 16,18,17,21,17,16, respectively). The formulae had < 0.1% 20:5n-3 and no arachidonic acid (20:4n-6). Breast-fed infants (n = 26) were also studied. Plasma phospholipid and red blood cell (RBC) phosphatidylcholine (PC) and phosphatidylethanolamine (PE) fatty acids were determined at 3 d and 4, 8, and 16 wk of age. These longitudinal analyses showed differences in blood lipid 22:6n-3 between breast-fed and formula-fed infants depending on the feeding duration. At 16 wk, infants fed formula with 0.10, 0.11% 22:6n-3, or 0.22% 22:6n-3 had similar 22:6n-3 levels in the plasma phospholipid and RBC PC and PE compared with breast-fed infants, and higher 22:6n-3 than infants fed formula without 22:6n-3. Formula with 0.24% 22:6n-3, however, resulted in higher plasma phospholipid 22:6n-3 than in breast-fed infants at 16, but not 4 or 8 wk of age. Plasma and RBC phospholipid 20:4n-6 was lower in formula-fed than breast-fed infants, but no differences in growth were found. Higher blood lipid C20 and C22 n-6 and n-3 fatty acids in infants fed formula with 20% 18:2n-6 and 2.4% 18:3n-3 compared with 32% 18:2n-6 and 4.9% 18:3n-3 show the increase in blood lipid 22:6n-3 in response to dietary 22:6n-3 depending on other fatty acids in the formula.

Docosahexaenoic acid status of term infants fed breast milk or infant formula containing soy oil or corn oil.

The objective of this study was to compare circulating lipid docosahexaenoic acid [22:6(n-3), DHA] levels in term infants fed a powdered (CORN oil) or liquid (SOY oil) infant formula or human milk (HM). Infants whose mothers chose not to breast feed were randomly assigned to the CORN or SOY formula group. The formula fat differed in linolenic acid [18:3(n-3)] content: it was 0.8% for the CORN and 4.8% for the SOY. Linoleic acid [18:2(n-6)] was 31.5 and 34.2% fatty acids in the CORN and SOY formula, respectively. The formulas or HM were fed from birth through 8 wk of age, and growth and the plasma and red blood cell (RBC) phospholipid fatty acid composition was determined at 3 d, 4 wk, and 8 wk of age. Growth did not differ among groups. The plasma phospholipid and RBC phosphatidylethanolamine DHA was similar in the CORN and SOY formula groups at all ages. Plasma and RBC phosphatidylethanolamine levels of DHA were significantly lower in infants fed the CORN or SOY formula than in infants fed HM during wk 4 and 8. Plasma and RBC 22:5(n-6) was not increased in the formula groups at any age. The formula content of linolenic acid had no effect on the RBC or plasma DHA levels of the infants. The biologic or functional significance of the lower plasma and RBC DHA in infants fed formula rather than HM is unknown. The need for a dietary source of DHA and specificity of plasma or RBC phospholipid DHA as a measure of desaturation and elongation of linolenic acid in developing organs remains uncertain.