title: Dietary benzo(a)pyrene and fetal growth: effect modification by vitamin C intake and glutathione S-transferase P1 polymorphism.
abstract: BACKGROUND
  Previous studies have reported maternal exposure to airborne polycyclic aromatic hydrocarbons (PAH), as well as DNA adducts reflecting total PAH exposure, to be associated with reduced fetal growth. The role of diet, the main source of PAH exposure among non-smokers, remains uncertain.
  
  
  OBJECTIVE
  To assess associations between birth weight, length and small size for gestational age (SGA) with maternal intakes of the genotoxic PAH benzo(a)pyrene [B(a)P] during pregnancy, exploring potential effect modification by dietary intakes of vitamin C, vitamin E, alpha- and beta-carotene, as well as glutathione S-transferase P1 (GSTP1) polymorphisms, hypothesized to influence PAH metabolism.
  
  
  METHODS
  657 women in the INMA (Environment and Childhood) Project from Sabadell (Barcelona) were recruited during the first trimester of pregnancy. Dietary B(a)P and nutrient intakes were estimated from food consumption data. Genotyping was conducted for the Ile105Val variant of GSTP1. Multivariable models were used to assess associations between size at birth and dietary B(a)P, evaluating potential interactions with candidate nutrients and GSTP1 variants.
  
  
  RESULTS
  There were significant interactions between elevated intakes of vitamin C (above the mean of 189.41 mg/day) and dietary B(a)P during the first trimester of pregnancy in models for birth weight and length (P<0.05), but no interactions were found with other nutrients. B(a)P intakes were associated with significant reductions in birth weight and length (coefficient±SE for a 1-SD increase in B(a)P: -101.63±34.62 g and -0.38±0.16 cm, respectively) among women with low, but not high, vitamin C intakes. Elevated dietary B(a)P was also associated with increased risk of SGA births among women with low dietary vitamin C. Among these women, associations were strongest in those carrying the GSTP1 Val allele, associated with lower contaminant detoxification activity.
  
  
  CONCLUSIONS
  Results suggest that dietary B(a)P exposure may impair fetal growth, particularly in genetically susceptible populations, and that increasing maternal intakes of vitamin C may help to reduce any adverse effects.
authors.affiliation: Centre for Research in Environmental Epidemiology, Barcelona, Spain. talitaduarte.salles@gmail.com
authors.forename: Talita
authors.initials: T
authors.lastname: Duarte-Salles
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Mendez
authors.forename: Eva
authors.initials: E
authors.lastname: Morales
authors.forename: Mariona
authors.initials: M
authors.lastname: Bustamante
authors.forename: Agueda
authors.initials: A
authors.lastname: Rodríguez-Vicente
authors.forename: Manolis
authors.initials: M
authors.lastname: Kogevinas
authors.forename: Jordi
authors.initials: J
authors.lastname: Sunyer
mesh_terms: D000328:Adult; D001205:Ascorbic Acid / Q000008:administration & dosage*; D001564:Benzo(a)pyrene / Q000008:administration & dosage* / Q000378:metabolism / Q000633:toxicity; D001724:Birth Weight / Q000187:drug effects; D018736:DNA Adducts; D004032:Diet / Q000706:statistics & numerical data; D004785:Environmental Pollutants / Q000008:administration & dosage* / Q000378:metabolism / Q000633:toxicity; D005260:Female; D047109:Fetal Development / Q000187:drug effects*; D020022:Genetic Predisposition to Disease / Q000453:epidemiology; D005982:Glutathione Transferase / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D008297:Male; D018811:Maternal Exposure; D011110:Polymorphism, Genetic; D011247:Pregnancy; D011248:Pregnancy Complications / Q000139:chemically induced; D014810:Vitamin E / Q000008:administration & dosage; D019207:beta Carotene / Q000008:administration & dosage
chemical_list: D018736:DNA Adducts; D004785:Environmental Pollutants; D019207:beta Carotene; D014810:Vitamin E; D001564:Benzo(a)pyrene; D005982:Glutathione Transferase; D001205:Ascorbic Acid