Lutein and Neurodevelopment in Preterm Infants

Carotenoids are pigments naturally occurring in plants, particularly in dark-green leafy vegetables such as raw spinach and cooked kale, and they have many functions in human tissues. Lutein is the dominant carotenoid found in adult and in infant brain especially in the neocortex and in the neural retina, however diet intake is needed because it cannot be synthesized in the body (Costa et al., 2013). Preterm infants have been deprived from carotenoid transfer during the last weeks of pregnancy and after birth the only sources are breast milk or oral supplementation. Concerning carotenoids, it has long been assumed that their intestinal absorption occurs by passive diffusion. Recently the high inter-individual variability in absorption observed in human studies argues in favor of the existence of putative membrane transporters of carotenoids. After uptake by the enterocyte, a substantial quantity of carotenoids up to 40% of the dietary intake is not metabolized. It is assumed that the major fraction of carotenoids are incorporated into chylomicrons that are secreted into the lymph (Reboul, 2013). Carotenoid composition of human milk changes during the first month postpartum. Lutein represents only 20% of carotenoids in colostrum but nearly 50% in mature milk. During the first month postpartum all four carotenoids (lutein, β-cryptoxanthin, lycopene, and α-carotene) decrease in the milk but lutein remains relatively elevated probably because it plays an important role for the infant (Gossage et al., 2002). Lutein concentration in breast milk correlates with mother plasma concentration and lutein intake during the third trimester of pregnancy. There is a dose-dependent response to lutein supplementation in lactating women. Previous studies (Sherry et al., 2014) demonstrated that lutein supplementation in pregnant women increases breast milk lutein concentration and provides plasma increase in their infants. Mothers who received higher doses of lutein supplementation had higher value of lutein concentration in plasma than mothers who received lower doses or placebo. However arterial cord blood lutein levels in addition to maternal plasma concentrations seem to be sex, gestational age and delivery mode dependent. Lutein levels are lower in males and in newborns delivered by cesarean section (Picone et al., 2012). However, post-mortem infant brain samples analyzed for lutein by HPLC did not show any difference in the levels of lutein between males and females (Lieblein-Boff et al., 2015). Arterial cord blood level of lutein is higher in preterm infants, especially at the early stage of the third trimester, than in term …