Plasma lipoprotein fatty acids are altered by the positional distribution of fatty acids in infant formula triacylglycerols and human milk

• Published in: The American journal of clinical nutrition Vol. 70; no. 1; pp. 62 - 69
• Main Authors: Nelson, C.M, Innis, S.M
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Bethesda, MD American Society for Clinical Nutrition 01.07.1999; American Society for Clinical Nutrition, Inc
• Subjects: Biological and medical sciences; blood chemistry; bottle feeding; breast feeding; breast milk; Cholesterol Esters - blood; Chylomicrons; Fatty acids; Fatty Acids - analysis; Fatty Acids - blood; Fundamental and applied biological sciences. Psychology; Humans; Infant; Infant Food; infant formulas; infants; lipid metabolism; lipoproteins; Lipoproteins - blood; Milk; Milk, Human - chemistry; molecular conformation; Mother. Fetoplacental unit. Mammary gland. Milk; palmitic acid; Pregnancy. Parturition. Lactation; Prospective Studies; triacylglycerols; Triglycerides - administration & dosage; Triglycerides - chemistry; Vertebrates: reproduction; Weight Gain; Human; Molecular structure; Lipids; Infant; Apolipoprotein; Palmitic acid; Fatty acids; Chylomicron; Triacylglycerol; Infant food; Human milk; Infant formula; Lipoprotein HDL
• ISSN: 0002-9165; 1938-3207

Background: Triacylglycerol digestion involves hydrolysis of fatty acids esterified at the glycerol 1,3 positions by gastric and pancreatic lipase to produce 2-monoacylglycerols and unesterified fatty acids, which are then absorbed, reesterified to triacylglycerol, and secreted in chylomicrons. Palmitic acid (16:0) is predominantly esterified to the 2 position of human milk triacylglycerol but to the 1,3 positions in the oils used in infant formulas. Objective: We aimed to determine whether the position of 16:0 in human milk and infant formula triacylglycerol influences the position of fatty acids in postprandial plasma chylomicron triacylglycerol. Design: Full-term infants were fed formula with 25-27% 16:0 with either 39% of the 16:0 (synthesized triacylglycerol) or 6% of the 16:0 (standard formula) esterified at the triacylglycerol 2 position, or were breast-fed (23% 16:0, 81% at the triacylglycerol 2 position) from birth to 120 d of age. Chylomicron fatty acids and plasma lipids were assessed at 30 and 120 d of age. Results: Infants fed the synthesized triacylglycerol formula, standard formula, or breast milk had 15.8%, 8.3%, and 28.0% 16:0 in the chylomicron triacylglycerol 2 position (P < 0.05). These results suggest that > or = 50% of the dietary triacylglycerol 2-position 16:0 is conserved through digestion, absorption, and chylomicron triacylglycerol synthesis in breast-fed and formula-fed infants. Infants fed the synthesized triacylglycerol formula had significantly lower HDL-cholesterol and apolipoprotein A-I and higher apolipoprotein B concentrations than infants fed the standard formula. Conclusion: Dietary triacylglycerol fatty acid distribution may alter lipoprotein metabolism in young infants.