Docosahexaenoic and arachidonic acid absorption in preterm infants fed LCP-free or LCP-supplemented formula in comparison to infants fed fortified breast milk

The absorption of long-chain polyunsaturated fatty acids (LCP) with particular respect to docosahexaenoic (DHA) and arachidonic acid (AA) has been studied in 39 very-low-birth-weight infants appropriate for gestational age after a 10-day feeding period. The infants were fed either a LCP-supplemented formula (n = 11), or a LCP-free formula (n = 11) or breast milk fortified with protein and carbohydrates to have similar protein and energy intakes as in the formula-fed infants (n = 17). Total fat content and fatty acid profile were measured in the human milk, the two formulas, and in the stool samples. After a 10-day feeding period, the fecal excretions of total fat, DHA and AA were measured during a 3-day balance period. The total fat apparent absorption rates were similar in all groups (84.1, 82.1 and 80.6% of intake, respectively). The DHA and AA intakes were significantly (p < 0.01) higher in the group fed the fortified breast milk than in the group fed the LCP-supplemented formula (DHA: 75.5 +/- 12.4 vs. 50.2 +/- 4.2 mg/72 h; AA: 45.5 +/- 5.8 vs. 30.2 +/- 2.7 mg/72 h). There was a tendency for lower apparent absorption rates for both LCPs studied in the group fed fortified breast milk when compared to the group fed LCP-supplemented formula (AA: 70.6 +/- 10.9 vs. 73.0 +/- 8.7% of intake, DHA: 69.0 +/- 10.6 vs. 74.2 +/- 9.5% of intake), but the differences were not significant. As consequence of the different intakes, the net absorption of the two studied LCP fatty acids were significantly (p < 0.01) higher in the breast milk group than in the group fed the LCP-supplemented formula (DHA: 52.6 +/- 6.1 vs. 36.8 +/- 4.5 mg/72 h; AA: 31.4 +/- 3.1 vs. 22.4 +/- 2.3 mg/72 h). The data demonstrate that DHA and AA are absorbed from the studied LCP-supplemented formula at least as effectively as from human milk. The net absorption of these LCP depend on the amount of dietary intake, and seems to be influenced by the dietary LCP source.