Docosahexaenoic acid (DHA) and arachidonic acid (AA) are the main long-chain polyunsaturated fatty acids (LCPUFA) of the brain and retinal cell membranes. Animals deficient in dietary n-3 fatty acids have low DHA content in their membranes and have reduced visual acuity and impaired learning ability. Adding DHA and AA to milk of bottle-fed human infants brings their blood concentrations to values as high as those observed in breast-fed infants and significantly improves their mental development and the maturation of their visual function. There is no evidence that LCPUFA supplementation of infant formula influences the growth of preterm or term infants in either a positive or a negative way.
Breast-feeding, which supplies LCPUFA, is therefore the preferred method of feeding for a healthy term infant. When breast-feeding is not possible, the addition of LCPUFA with appropriate regard for quantitative and qualitative qualities in infant formulas is recommended and should be in the range found in human milk typical of mothers in western countries. It should provide DHA at levels between 0.2 and 0.5% of total fat with at least an equivalent amount of AA.