title: Modulation of DNA methylation states and infant immune system by dietary supplementation with ω-3 PUFA during pregnancy in an intervention study.
abstract: BACKGROUND
  Early-life exposures to tobacco smoke and some dietary factors have been identified to induce epigenetic changes in genes involved in allergy and asthma development. Omega-3 (n-3) polyunsaturated fatty acid (PUFA) intake during pregnancy could modulate key cytokines and T helper (Th) cell maturation; however, little is known about the mechanism by which ω-3 PUFA could have a beneficial effect in preventing inflammatory disorders.
  
  
  OBJECTIVE
  We sought to test whether prenatal dietary supplementation with ω-3 PUFA during pregnancy may modulate epigenetic states in the infant immune system.
  
  
  METHODS
  This study was based on a randomized intervention trial conducted in Mexican pregnant women supplemented daily with 400 mg docosahexaenoic acid (DHA) or a placebo from 18 to 22 wk of gestation to parturition. We applied quantitative profiling of DNA methylation states in Th1, Th2, Th17, and regulatory T-relevant genes as well as LINE1 repetitive elements of cord blood mononuclear cells (n = 261).
  
  
  RESULTS
  No significant difference in promoter methylation levels was shown between ω-3 PUFA-supplemented and control groups for the genes analyzed; however, ω-3 PUFA supplementation was associated with changes in methylation levels in LINE1 repetitive elements (P = 0.03) in infants of mothers who smoked during pregnancy. Furthermore, an association between the promoter methylation levels of IFNγ and IL13 was modulated by ω-3 PUFA supplementation (P = 0.06).
  
  
  CONCLUSIONS
  Our results indicate that maternal supplementation with ω-3 PUFA during pregnancy may modulate global methylation levels and the Th1/Th2 balance in infants. Therefore, the epigenetic mechanisms could provide attractive targets for prenatal modulation and prevention of inflammatory disorders and potentially other related diseases in childhood and adulthood.
authors.affiliation: International Agency for Research on Cancer, Lyon, France.
authors.forename: Ho-Sun
authors.initials: HS
authors.lastname: Lee
authors.forename: Albino
authors.initials: A
authors.lastname: Barraza-Villarreal
authors.forename: Hector
authors.initials: H
authors.lastname: Hernandez-Vargas
authors.forename: Peter D
authors.initials: PD
authors.lastname: Sly
authors.forename: Carine
authors.initials: C
authors.lastname: Biessy
authors.forename: Usha
authors.initials: U
authors.lastname: Ramakrishnan
authors.forename: Isabelle
authors.initials: I
authors.lastname: Romieu
authors.forename: Zdenko
authors.initials: Z
authors.lastname: Herceg
mesh_terms: D000293:Adolescent; D000328:Adult; D019175:DNA Methylation / Q000187:drug effects*; D019587:Dietary Supplements; D004311:Double-Blind Method; D044127:Epigenesis, Genetic; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage* / Q000097:blood; D005260:Female; D006801:Humans; D007107:Immune System / Q000187:drug effects*; D007223:Infant; D007371:Interferon-gamma / Q000097:blood / Q000235:genetics; D018793:Interleukin-13 / Q000097:blood / Q000235:genetics; D016014:Linear Models; D008800:Mexico; D015999:Multivariate Analysis; D011247:Pregnancy; D039401:Prenatal Nutritional Physiological Phenomena; D011401:Promoter Regions, Genetic; D017422:Sequence Analysis, DNA; D058408:Th1-Th2 Balance / Q000187:drug effects; D055815:Young Adult
chemical_list: D015525:Fatty Acids, Omega-3; D018793:Interleukin-13; D007371:Interferon-gamma