reached school age, when more sophisticated measures of cognitive function may be employed.
Reviews of the effects of fatty acid supplementation on immune function in the neonate have not provided strong support for beneficial effects (Calder et al., 2001; Field et al., 2001) (see Appendix Table B-1h). One human study showed positive effects of human milk and formulas containing DHA and AA compared to formulas without DHA and AA in the form of lower CD4RO+ immune cells and IL-10 cytokine production (Field et al., 2000). However, experimental studies of DHA-supplemented lactating women have not found any effect of supplementation on milk cytokines at intakes as high as 140 mg/day EPA and 600 mg/day DHA (Hawkes et al., 2002) or 3.7 g EPA/DHA from fish oil (28 percent EPA and 56 percent DHA) in a group selected to be at high risk for allergic disease (Denburg et al., 2005).
The strongest evidence of benefit for postnatal DHA supplementation in formula-fed preterm and term infants is higher visual acuity, an outcome that has been measured repeatedly in clinical trials. In addition, some positive effects have been found on cognitive function in infancy and childhood in both experimental and observational studies and in relation to both pre- and postnatal DHA intake. Reviews that take into account all lines of evidence have concluded that omega-3 fatty acids can be beneficial to cognitive development (Cohen et al., 2005; McCann and Ames, 2005), whereas reviews that rely strictly on published results from experimental trials limited to global assessments of cognitive development, e.g., the MDI, do not offer strong support (Simmer, 2005; Simmer and Patole, 2005).
Results of some experimental trials suggest that postnatal DHA infant formula supplementation benefits cognitive function as well. Specific behavioral domains such as novelty preference and duration of looking are more related to later function than global tests of development (Carlson and Neuringer, 1999; Jacobson, 1999). Bryan et al. (2004) and Cheatham et al. (2006) postulate that benefits associated with postnatal infant formula supplementation may have been underestimated as a result of the emphasis on global tests of infant development as well as the paucity of outcomes measured in childhood.