Palmitic Acid in Early Human Development

Palmitic acid (16: 0) is a saturated fatty acid present in the diet and synthesized endogenously. Although often considered to have adverse effects on chronic disease in adults, 16: 0 is an essential component of membrane, secretory, and transport lipids, with crucial roles in protein palmitoylation and signal molecules. At birth, the term infant is 13-15% body fat, with 45-50% 16: 0, much of which is derived from endogenous synthesis in the fetus. After birth, the infant accumulates adipose tissue at high rates, reaching 25% body weight as fat by 4-5 months age. Over this time, human milk provides 10% dietary energy as 16: 0, but in unusual triglycerides with 16: 0 on the glycerol center carbon. This paper reviews the synthesis and oxidation of 16: 0 and possible reasons why the infant is endowed with large amounts of fat and 16:0. The marked deviations in tissues with displacement of 16: 0 that can occur in infants fed vegetable oil formulas is introduced. Assuming fetal fatty acid synthesis and the unusual delivery of 16: 0 in human milk evolved to afford survival advantage to the neonate, it is timely to question if 16: 0 is an essential component of tissue lipids whereby both deficiency and excess are detrimental.