We investigated whether the disparity in neural maturation between bre
astfed and formula-fed term infants could be corrected by the addition
of fish oil, a source of docosahexaenoic acid (DHA, 22:6 omega 3), to
infant formula. Healthy, term infants were randomised at birth to rec
eive either a supplemented or placebo formula if their mothers had cho
sen to bottle feed. Breastfed term infants were enrolled as a referenc
e group. Infant erythrocyte fatty acids and anthropometry were assesse
d on day 5 and at 6, 16, and 30 weeks of age. Visual evoked potential
(VEP) acuity was determined at 16 and 30 weeks. VEP acuities of breast
fed and supplemented-formula-fed infants were better than those of pla
cebo-formula-fed infants at both 16 and 30 weeks of age (p<0.001 and p
<0.01). Erythrocyte DHA in breastfed and supplemented-formula-fed infa
nts was maintained near birth levels throughout the 30-week study peri
od but fell in placebo-formula-fed infants (p<0.001). Erythrocyte DHA
was the only fatty acid that consistently correlated with VEP acuity i
n all infants at both ages tested. A continuous supply of DHA may be r
equired to achieve optimum VEP acuity since infants breastfed for shor
t periods (<16 weeks) had slower development of VEP than infants recei
ving a continuous supply of DHA from either breastmilk or supplemented
formula. Erythrocyte arachidonic acid (20:4 omega 6) in supplemented-
formula-fed infants was reduced below that of infants fed breastmilk o
r placebo formula at 16 and 30 weeks (p<0.001), although no adverse ef
fects were noted, with growth of all infants being similar. DHA seems
to be an essential nutrient for the optimum neural maturation of term
infants as assessed by VEP acuity. Whether supplementation of formula-
fed infants with DHA has long-term benefits remains to be elucidated.