RESUMO
The present study is a trial to evaluate the effect of breast feeding versus artificial feeding on serum lipids in infants and older age groups. Serum lipids including triglycerides [TG] and total cholesterol [TC], serum lipoproteins including high density lipoprotein-cholesterol [HDL-C], low density lipoprotein-cholesterol [LDL-C], and very low density lipoprotein-cholesterol [VLDL-C], and serum apolipoproteins A, A-I, and B [Apo A, Apo A-I, and Apo B] were determined in 250 infants and children classified into 2 groups : one group, 200, aged 2-24 months, half of them breast fed and the other half artificially fed. The second group, 50, aged 6-12 years, half of them had a history of breast feeding in infancy for different periods, and the other half had a history of artificial feeding. School aged children with a history of breast feeding for a period more than 1 year showed significantly lower serum levels of TC, TG, LDL-C, VLDL-C, Apo B, and values of the atherosclerotic index [Apo B/Apo A-I], and significantly higher serum levels of HDL-C, Apo A, Apo A-I and values of the protective indices against vascular disease [Apo A-I/Apo B, and HDL-C/TC] than those with a history of artificial feeding. In addition, children with a history of breast feeding for a period more than 1 year showed significantly higher serum levels of HDL-C, Apo-A, Apo A-I, and Apo A-I/Apo B values and significantly lower serum TG levels than those with a history of breast feeding for a short period [6-12 months]. While this later group showed significantly lower serum levels of LDL-C, VLDL-C, and Apo B, and significantly higher Apo A-I/Apo B and HDL-C/TC values than those with a history of artificial feeding. Furthermore, breast fed children aged 18 to 24 months showed significantly higher serum levels of Apo A-I and values of Apo A-I/Apo B index than artificially fed group of the same age. These deferred favourable effects of breast feeding on serum lipids, lipoproteins, and apolipoproteins-with an expected low risk to atherosclerosis-are the reverse of the early apparently unfavourable effects during infancy and early childhood, as breastfed infants and young children less than 18 months of age showed significantly higher serum levels of TG, TC, LDL-C, VLDL-C, Apo B, and Apo B/Apo A-I values, and significantly lower values of Apo A-I/Apo B, and HDL-C/TC than artificially fed group of the same age. We can conclude that breast feeding-especially when prolonged-plays a role in the protection against hyperlipidemia later in childhood. This protective effect may appear as early as the age of 18 months