Departments of Pediatrics, Obstetrics and Gynecology, Wayne State University, Detroit, Michigan, USA. wkoo@wayne.edu
Long chain polyunsaturated fatty acids (LCPUFA) namely arachidonic acid (ARA, 20:4n-6) and docosahexaenoic acid (DHA, 22:6n-3) are highly concentrated in the phospholipid bilayer of biologically active brain and retinal neural membranes and are important in phototransduction and neuronal function. The rationale for adding these LCPUFA to infant formula (IF) was primarily because of their presence in large quantities in the retina and brain and in human milk. In addition, infants fed IF containing LCPUFA and breastfed infants have comparable ARA and DHA levels in red cell and plasma, in contrast to the lower ARA and DHA levels in those fed IF containing only the essential fatty acids: linoleic (LA, 18:2n-6) and linolenic (LNA, 18:3n-3), the precursors to ARA and DHA, respectively. However, functional benefits in particular visual or neural development from IF containing LCPUFA remains controversial. Potential for excessive and/or imbalanced intake of n-6 and n-3 fatty acids exists with increasing fortification of LCPUFA to infant foods other than IF.