EFFECTS OF DIET ON FATTY ACID COMPOSITION OF PLASMA AND RED CELL PHOSPHOGLYCERIDES IN THREE-MONTH-OLD INFANTS

Concentrations of the main lipid classes in plasma and the blood phosphoglyceride fatty acid patterns were measured in 3-month-old infants, fed breast-milk or an industrial manufactured formula. The levels of cholesterol and phosphoglycerides were in the normal range for young adults, but the triglyceride concentration was twice as high as in adults. There were no significant differences in the levels of the plasma lipids between the two groups, but the mean of the triglycerides was 25 % higher in the formula-fed group. The plasma and red cell phosphoglycerides had already assumed a fatty acid pattern of adult type. The concentration of the total polyenoic acids was significantly lower in the breast-fed group, the difference being entirely confined to the fatty acids of the linoleic acid series. Linoleic acid was 27% and 40%, respectively, lower in plasma phosphoglycerides and red cell lecithin of breast-fed than of formula-fed infants, but arachidonic acid did not show any significant difference in the two groups. The concentration of the fatty acids of the linolenic acid series was higher in the breast-fed infants. The blood lecithin ratio between the fatty acids of the linolenic acid series and the linoleic acid series was thus much lower in the formula-fed than in the breast-fed infants, the ratio being closely correlated with the dietary linolenate/linoleate ratio. Although the concentration of essential fatty acids was low in both plasma and red cell phosphoglycerides of breast-fed infants, there was no increase of 20: 3 (n – 9).