title: Genetic variants in the FADS gene cluster are associated with arachidonic acid concentrations of human breast milk at 1.5 and 6 mo postpartum and influence the course of milk dodecanoic, tetracosenoic, and trans-9-octadecenoic acid concentrations over the duration of lactation.
abstract: BACKGROUND
  Breastfeeding is considered an optimal nutritional source of n-6 (omega-6) and n-3 (omega-3) fatty acids (FAs) for the proper visual and cognitive development of newborn children. In addition to maternal nutrition as an important regulator of FA concentrations, first results exist on an association of breast-milk FAs with single nucleotide polymorphisms (SNPs) in the FADS gene cluster, which encodes the rate-limiting enzymes in the elongation-desaturation pathway of long-chain polyunsaturated fatty acids (LC-PUFAs).
  
  
  OBJECTIVE
  We analyzed the influence of FADS SNPs on breast-milk FA concentrations and their time course during lactation in the Ulm Birth Cohort study, which comprised 772 nursing mothers at 1.5 mo after giving birth, and in a subset of 463 mothers who were still breastfeeding at 6 mo postpartum.
  
  
  METHODS
  We conducted linear regression analysis of 8 FADS SNPs with FA concentrations at both time points separately and assessed the genotype effect over time in a longitudinal analysis by using a generalized estimating equation regression model.
  
  
  RESULTS
  We observed significant associations of FADS genotypes with arachidonic acid (AA) concentrations and the 20:4n-6/20:3n-6 ratio at both time points but no association of FADS SNPs with the time course of AA concentrations. A longitudinal analysis of FAs other than LC-PUFAs by genotype over time showed associations for dodecanoic acid, cis-15-tetracosenoic acid, and trans-9-octadecenoic acid.
  
  
  CONCLUSIONS
  Maternal FADS genotypes are associated with breast-milk AA concentrations and might therefore influence the supply of this FA for children. Furthermore, our data indicate an interrelation between the LC-PUFA pathway and saturated and monounsaturated FAs.
authors.affiliation: Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Epidemiology, Neuherberg, Germany. eva.lattka@helmholtz-muenchen.de
authors.forename: Eva
authors.initials: E
authors.lastname: Lattka
authors.forename: Peter
authors.initials: P
authors.lastname: Rzehak
authors.forename: Éva
authors.initials: É
authors.lastname: Szabó
authors.forename: Viktoria
authors.initials: V
authors.lastname: Jakobik
authors.forename: Melanie
authors.initials: M
authors.lastname: Weck
authors.forename: Maria
authors.initials: M
authors.lastname: Weyermann
authors.forename: Harald
authors.initials: H
authors.lastname: Grallert
authors.forename: Dietrich
authors.initials: D
authors.lastname: Rothenbacher
authors.forename: Joachim
authors.initials: J
authors.lastname: Heinrich
authors.forename: Hermann
authors.initials: H
authors.lastname: Brenner
authors.forename: Tamás
authors.initials: T
authors.lastname: Decsi
authors.forename: Thomas
authors.initials: T
authors.lastname: Illig
authors.forename: Berthold
authors.initials: B
authors.lastname: Koletzko
mesh_terms: D000328:Adult; D016718:Arachidonic Acid / Q000378:metabolism*; D044943:Fatty Acid Desaturases / Q000235:genetics*; D005227:Fatty Acids / Q000378:metabolism*; D005229:Fatty Acids, Monounsaturated / Q000378:metabolism; D005260:Female; D005838:Genotype; D006801:Humans; D007774:Lactation / Q000378:metabolism*; D007850:Lauric Acids / Q000378:metabolism; D016014:Linear Models; D008137:Longitudinal Studies; D008895:Milk, Human / Q000378:metabolism*; D020641:Polymorphism, Single Nucleotide; D049590:Postpartum Period; D013229:Stearic Acids / Q000378:metabolism
chemical_list: C114874:5-octadecenoic acid; D005227:Fatty Acids; D005229:Fatty Acids, Monounsaturated; D007850:Lauric Acids; D013229:Stearic Acids; C030358:lauric acid; C064583:tetracosenoic acid; D016718:Arachidonic Acid; D044943:Fatty Acid Desaturases