Search for optimal age for weaning. Ten-year prospective study

The effect of infant nutrition on some clinical and biochemical parameters was studied from birth in a longitudinal prospective study. The data covering the period up to 7 years were reported previously. At the age 10 years 80 children were examined. Two children have been regularly followed up because of high blood pressure. Both had been breast-fed for less than one week and are obese at present. Surprisingly serum total cholesterol was the highest in the group breast-fed for more than 6 months. There were no pronounced differences in the levels of lipoprotein cholesterol carriers. The incidence of a high (over 6.0) atherogenic index (total chol - HDL chol) x APOB/APOA1 x HDL chol) and cholesterolemia over 4.8 mmol/l was significantly (chi 2 test) higher in the group breast-fed for over 6 months. Thyroid function parameters were not affected by the duration of breast-feeding. We conclude that besides undoubtedly favorable effects of breast-feeding, some functions might be also adversely affected if it lasts for more than 6 months. For justified recommendation of optimal duration of breast-feeding all aspects should be considered and more data collected.