title: Interaction of n-3 long-chain polyunsaturated fatty acids with n-6 fatty acids in suckled rat pups.
abstract: 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.
authors.affiliation: Wyeth Nutritionals International, Philadelphia, Pennsylvania 19101, USA.
authors.forename: F G
authors.initials: FG
authors.lastname: Boyle
authors.forename: R J
authors.initials: RJ
authors.lastname: Yuhas
authors.forename: K
authors.initials: K
authors.lastname: Goldberg
authors.forename: E L
authors.initials: EL
authors.lastname: Lien
mesh_terms: D000818:Animals; D000833:Animals, Suckling / Q000378:metabolism*; D001835:Body Weight / Q000502:physiology; D001921:Brain / Q000378:metabolism; D004041:Dietary Fats / Q000378:metabolism; D015525:Fatty Acids, Omega-3 / Q000378:metabolism*; D043371:Fatty Acids, Omega-6; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D008099:Liver / Q000378:metabolism; D010743:Phospholipids / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D013270:Stomach / Q000737:chemistry
chemical_list: D004041:Dietary Fats; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D005231:Fatty Acids, Unsaturated; D010743:Phospholipids