Foetal cord blood contains higher portions of n-3 and n-6 long-chain PUFA but lower portions of trans C18:1 isomers than maternal blood

Background/objective : An adequate supply of long-chain polyunsaturated fatty acids (LC PUFA) promotes foetal health and development, whereas generally, trans fatty acids ( t FA) are considered to negatively interfere with LC PUFA metabolism. Nevertheless, to date, limited data concerning separate trans C18:1, such as t 9 and t 11, are available for maternal and foetal blood. Therefore, in this study the portions of individual trans C18:1, LC n-6, and n-3 PUFA in lipids of maternal and foetal plasma and erythrocyte membranes of German mother and child pairs ( n= 40) were analysed. Results : Portions of linoleic acid and α-linolenic acid as LC precursors were lower (~0.4-fold); whereas the metabolites arachidonic acid (AA, n-6) and docosahexaenoic acid (DHA, n-3) were significantly higher (~2-fold) in foetal than in maternal plasma and erythrocytes. The main t FA in maternal and foetal blood were elaidic acid (C18:1 t 9; t 9) and vaccenic acid (C18:1 t 11; t 11). Portions of t 9, t 10, t 11, and t 12 in foetal blood lipids were lower (~0.5-fold) compared with maternal blood. In foetal lipids, t 9 was higher than t 11. The t 9 correlated negatively with eicosapentaenoic acid (n-3) and AA in maternal and foetal lipids; whereas t 11 correlated negatively only with foetal total LC n-6 (plasma and erythrocytes) and n-3 PUFA (erythrocytes). No correlation between maternal t FA and foetal PUFA was observed. Conclusions : ‘Biomagnification’ of LC n-6 and n-3 PUFA AA and DHA in foetal blood was confirmed, whereas single trans isomers were lower compared with maternal blood. Nevertheless, t FA intake, especially from industrial sources, should be as low as possible. Keywords: conjugated linoleic acids; pregnancy; trans fatty acids; elaidic acid; vaccenic acid; ruminant fat; omega-3 fatty acids (Published: 27 November 2015) Citation: Food & Nutrition Research 2015, 59: 29348 - http://dx.doi.org/10.3402/fnr.v59.29348