EFFECT OF DIET DURING THE FIRST SIX TO EIGHT WEEKS OF LIFE ON TOTAL CONCENTRATIONS OF SERUM PROTEIN AND ON ELECTROPHORETIC PATTERNS OF SERUM PROTEIN AND LIPOPROTEIN

Abstract

The total protein, lipid and cholesterol concentrations, and the protein and lipoprotein electrophoretic patterns found in the sera of mothers at term, cord blood and the venous blood of 6-to-8-week-old infants born at term are reported. The infants were subdivided into four test groups on the basis of dietary intake of protein and fat. The pertinent characteristics of the test diets are as follows: Diet I—15% of the calories derived from cow milk protein and 35% from butterfat; Diet II—19% of the calories derived from soya protein and 35% from a blend of soya and coconut oils; Diet III—14% of the calories derived from cow milk protein and 40% from a blend of corn, coconut and olive oils; Diet IV—9% of the calories derived from cow milk protein and 50% from a blend of stearinated beef fat, coconut and corn oils. Linoleic acid composed about 1.2% of the dietary fat in Diet I, 39.2% in Diet II, 30.1% in Diet III and 21.7% in Diet IV. The mean values for total protein concentrations in serum among the four test groups did not differ significantly from each other or from that found in cord sera. The electrophoretically determined albumin: globulin ratios in the four groups of test infants were essentially the same and did not differ significantly from that found in cord sera. In relation to cord sera, all groups of test infants showed a similar decline in the relative and absolute concentrations of gamma-globulin. These results are comparable to those reported in the literature by other workers. When compared with the mean values present in cord sera, the total lipid and total cholesterol concentrations in the sera of all groups of test infants were significantly greater. Among the groups of test infants, these values were significantly greater in those receiving Diet I (dietary fat predominantly butterfat). Differences among the groups receiving Diets II, III and IV were not significant. In contrast to "normal" adults in whom paper electrophoresis indicates that approximately 30% of the lipids are found in the alpha-lipoprotein fraction and 70% in the beta-lipoprotein fraction, cord blood contained approximately 40% in the alpha-lipoprotein fraction and 60% in the beta-lipoprotein fraction. The cord blood lipoprotein pattern tended to persist in the sera of those infants receiving Diets II, III and IV, while the pattern in the sera of infants receiving Diet I approached that of "normal" adult sera. Within the framework of this study, neither the quantity nor the quality of the dietary protein appeared to exert an effect upon lipid concentrations and lipoprotein patterns. Similarly neither the quantity nor the quality of dietary fat appeared to have an effect upon total protein concentrations or electrophoretic patterns. These studies suggest that neither total protein concentrations in serum nor electrophoretic patterns are particularly sensitive indexes of the nutritional efficacy of infant dietaries providing 9 to 19% of their calories as protein of good biologic quality. Neither the short-term or long-term nutritional or clinical significance of the effects on lipids of the various types of dietary fat employed in these studies is apparent. However these studies do demonstrate the possibility of altering lipid concentrations in serum and lipoprotein distributions, should future investigations illustrate the wisdom of so doing.