EFFECTS OF A LOW-BIRTH-WEIGHT INFANT FORMULA CONTAINING HUMAN-MILK LEVELS OF DOCOSAHEXAENOIC AND ARACHIDONIC ACIDS

Long-chain (LC) polyunsaturated fatty acids (PUFA) (LCP) are considere d conditionally essential nutrients for low birth weight infants (LBWI ). Therefore, enrichment of LBWI formulae with metabolites both linole ic (omega-6) and alpha-linolenic (omega-3) acids at levels typical for human milk has been recommended. However, previous feeding trials wit h LCP-enriched formulae evaluated only a dietary supplementation with omega-3 LCP from fish oils alone or with both omega-3 and omega-6 LCP at levels considerably lower than usual human milk contents. We studie d the effects of an LBWI formula providing the major omega-3 and omega -6 LCP, docosahexaenoic and arachidonic acids, in amounts similar to t hose in average human milk. Twenty-seven LBWIs were enrolled in this s tudy when they tolerated full enteral feeding (greater than or equal t o 130 mi milk/kg/day). Infants either received their own mother's milk (n = 8, birthweight 1218 +/- 146 g, gestational age 30.2 +/- 1.5 week s, mean +/- SD) fortified with protein and minerals (FM-85, Nestle Ag, Munchen, Germany; dosage 5 g/100 mi milk) or were randomly assigned t o blinded batches of an LBWI formula (Prematil, Milupa AG, Friedrichsd orf, Germany) without LCP (n = 10, 1280 +/- 229 g, 31.1 +/- 3.1 weeks) or with LCP (n = 9, 1253 +/- 334 g, 30.4 +/- 3.3 wks.). During the st udy period of 21 days, the three feeding groups did not differ in grow th and feeding tolerances as assessed by occurrence of gastric residua ls, spitting, or abdominal distention; however, firms stools were note d more frequently in the two formula groups. Compared to infants fed h uman milk, those on formula without LCP showed significant depletion o f plasma phospholipid arachidonic acid (reduced to 74% of levels found in infants fed human milk) and, even more marked, of docosahexaenoic acid (reduced to 64%) as well as total LCP (74%), within 3 weeks of fu ll enteral feeding. In contrast, infants receiving the LCP-enriched fo rmula achieved an LCP status equal to that of human milk-fed babies. R esults indicate that LBWI absorb formula LCPs and incorporate them int o endogenous phospholipids. There were no adverse effects of LCP enric hment on vitamin-E status. We conclude that the LCP enrichment of the formula used in this study was well tolerated, did not interfere with short-term growth or vitamin-E status, and provided sufficient amounts of essential fatty acids to match the omega-3 and omega-6 LCP status of infants fed human milk.