Abstract
Purpose: :
Little is known about the development of macular pigment (MP) and its possible role in infant vision. Lutein, a major component of MP, is obtained solely from the diet, and typically is present in human milk at higher concentrations than in infant formula. Our objective was to measure serum lutein, macular pigment and visual function in infants fed human milk or formulas with and without added lutein.
Methods: :
In a prospective, double-masked study, healthy term formula-fed infants (n=26) were randomized at 9-16 days of age to formulas containing 20 (unfortified), 45, 120, and 225 mcg/L of lutein. They were compared with a breastfed reference group (n=14). At 12 weeks, MP optical density was measured by 4-wavelength reflectometry, and visual acuity and contrast sensitivity at 0.5 and 2 cycles/degree were determined by a swept-parameter visual evoked potential method.
Results: :
At week 12 the breastfed infants, who consumed human milk with a mean lutein concentration of 21 mcg/L, had 6-fold higher mean serum lutein than the unfortified formula group. Mean serum lutein increased from baseline in each formula group except the unfortified group. The range of MP densities was 0.0-0.39 AU. The highest MP was in the breastfed group, but at least one infant in each group had no detectable MP. Visual acuity and contrast sensitivity were similar across groups. Contrast sensitivity at 2 cpd was positively related to serum lutein levels in breastfed but not formula-fed infants.
Conclusions: :
Breastfed infants have higher serum lutein concentrations than infants who consume unfortified formula. Four-wavelength reflectometry can be used in human infants to estimate MP density. MP densities in infants are highly variable, and therefore larger studies will be needed to assess relationships of early lutein intake to MP development.
Keywords: macular pigment • nutritional factors • infant vision