Programming of cholesterol metabolism by breast or formula feeding.

We tested the hypothesis that breast or formula feeding and cholesterol intake during the neonatal period influence cholesterol metabolism and arterial fatty streaks in young adult baboons. Genetic variation was controlled by randomly assigning half-sib sire progeny to a factorial dietary design. We measured serum cholesterol and lipoprotein cholesterol concentrations enzymically and cholesterol production and bile acid excretion rates isotopically. The bile cholesterol saturation index was calculated from enzymic analyses of cholesterol, bile salt and phospholipid concentrations in gallbladder bile. Breast-fed baboons had higher serum VLDL + LDL cholesterol/HDL cholesterol ratios in the early postweaning period (six months) until adulthood (7-8 years) than formula-fed baboons. In adulthood a high cholesterol diet increased bile acid excretion by approximately 40% in formula-fed baboons but did not significantly increase the bile acid excretion rate among breast-fed animals. Adult baboons breast fed as infants also had an approximately 8% lower cholesterol production rate than formula-fed animals and a 20% higher bile cholesterol saturation index. The level of cholesterol in the infant formulas influenced cholesterol metabolism in adulthood but not serum lipoprotein concentrations. As young adults, breast-fed baboons had more extensive arterial fatty streaks than formula-fed baboons. This difference could be accounted for by differences in the lipoprotein ratios. These results demonstrate that breast and formula feeding differentially modify cholesterol metabolism. This may influence the development of chronic diseases.