These studies provide evidence that palmitic acid can be efficiently absorbed, avoiding fatty soap formation of it is present in the sn-2 position.

The addition of long-chain polyunsaturated fatty acids (LCP: C20, and C22) to infant formula may permit fatty acid accretion rates similar to breast-fed infants, and may have long-term outcome benefits, such as improved visual acuity and cognitive development. Although fish oil may provide a source of n-3 LCP, sources of n-6 LCP have been more difficult to identify. The present study evaluates the effects of n-3 and n-6 LCP derived from single-cell oils on liver, plasma, and brain fatty acid levels in a neonatal animal model. Newborn rat pups were suckled for 14 d by dams receiving diets containing n-3 LCP alone or combinations of n-3 LCP and increasing doses of linoleic acid (18:2n-6) or arachidonic acid (20:4n-6). Dietary groups received 2% n-3 LCP and 1, 2, or 5% of either 18:2n-6 or 20:4n-6. The 20:4n-6 source also contained modest levels of 18:2n-6. At the termination of the study, liver, plasma, and brain were obtained from the rat pups and the phospholipid fatty acid profiles determined. The results indicate complex interactions of n-3 and n-6 fatty acids. Groups receiving dietary 20:4n-6 incorporated higher levels of n-6 LCP into tissues than did the groups receiving 18:2n-6. The brain was relatively resistant to changes in fatty acid composition compared with the liver and plasma. As expected, tissue n-3 LCP levels were reciprocally related to n-6 levels. The present results document that single-cell LCP oils are bioavailable in a neonatal animal model. The use of 20:4n-6 is a more effective means of supporting n-6 status than the use of 18:2n-6. These results may have implications for the addition of LCP to infant formula.

No abstract

Soy oil or corn oil may be employed to provide essential fatty acids in infant formulas. Both of these sources are high in linoleic acid; soy oil contains modest levels of α-linolenic acid, while corn oil contains very low levels of this essential ω3 fatty acid. We examined the ω3 long-chain polyunsaturated fatty acid (LCP) accretion in red blood cells, liver, and brain phos-pholipids of rats on diets containing infant formula fat blends with essential fatty acids provided from soy and/or corn oil. Although modest alterations occurred in the red blood cell ω3 LCP fatty acid status, substantially larger changes were noted in liver LCP profiles. Due to the relatively mature nature of the rats employed in this experiment, no alterations were noted in brain fatty acid profiles. In conclusion, we have observed substantial tissue differences in animals fed soy or corn oil containing diets. It appears that corn oil is inappropriate for use in infant formulas.