John D. Benson

Docosahexaenoic Acid Status of Term Infants Fed Breast Milk or Infant Formula Containing Soy Oil or Corn Oil

ABSTRACT: 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.

Gastrointestinal tolerance, fat absorption, plasma ketone and urinary dicarboxylic acid levels in low-birth-weight infants fed different amounts of medium-chain triglycerides in formula

This study was conducted to evaluate the effect of medium-chain triglycerides (MCT) in a formula for low-birth-weight (LBW) infants on gastrointestinal tolerance, fat absorption, plasma ketone levels, and urinary dicarboxylic acid (DCA) excretion. At the start of enteral feedings, 64 LBW infants (≤1500 g) were randomly assigned to one of four experimental formulas. The formulas contained either 0, 17, 34, or 50% of the total fat as MCT oil. The nonfat constituents of all four formulas were the same and identical to Similac Special Care 24 (SCF), Infants were studied from the start of enteral feeding until approximately 7 days after reaching full feeds. Growth and tolerance were assessed in all infants over the entire feeding period. A 48-h balance study was conducted after enteral intake exceeded 100 kcal/kg/day for 3 days. Stool fat, plasma D-(—)-3-hydroxybutyrate (3HB) and carnitine, serum glucose, and urinary DCA levels were determined. Groups did not differ in growth, formula intake, fat absorption (76–84%), serum glucose, or plasma carnitine levels. Gastrointestinal tolerance was excellent and did not differ among groups. Plasma 3HB was significantly different (p < 0.05) only between the 0 and 50% MCT groups, 50 ± 10 versus 120 ± 20 μM, respectively. The excretion of urinary DCAs increased with increasing amounts of MCT in the formula. In conclusion, fat absorption and gastrointestinal tolerance were not affected by different MCT levels (0 to 50% of the total fat), but higher levels of plasma 3HB and urinary DCAs were associated with higher levels of MCT in the LBW formulas studied.