Effects of developmental changes and early nutrition on cholesterol metabolism in infancy: a review.
Plasma cholesterol levels usually range between 50 and 100 mg/dl at birth, with the cholesterol approximately equally distributed between low-density lipoprotein (LDL) and high-density lipoprotein (HDL). Plasma cholesterol increases rapidly over the first days after birth, predominantly due to an increase in cholesterol with LDL, irrespective of whether the infant is breast fed or fed with infant formulas. With continued feeding, plasma cholesterol becomes progressively, and significantly, higher in infants who are breast fed compared to those fed low-cholesterol, polyunsaturated fatty acid-rich infant formula. Studies in the developing young of other species have suggested that up-regulation of cholesterol synthesis, or turnover and excretion, at stages when these pathways are acquiring functional maturity may have lasting effects on cholesterol metabolism. The information available, however, indicates the diet-related differences in plasma cholesterol of the more mature human newborn are temporal in nature and probably not of significance to adult cardiovascular disease. Infants born early in the third trimester of gestation, however, are at risk for marked elevations in plasma cholesterol, with stimulation of endogenous cholesterol biosynthesis, as a result of the intravenous nutrition required to sustain life. Whether this has long-term consequences for this group of infants is unknown. There is presently no reason to advocate diet modification to alter the plasma cholesterol of normal infants under the age of 2 years.