title: Maternal diet and breastfeeding: a case for rethinking physiological explanations for breastfeeding determinants.
abstract: BACKGROUND
  Although some authors explain determinants of breastfeeding that occur in a dose-response manner as evidence of causality, we argue that dose-response relationships are not proof of a biological relationship between the variables. The relationship between maternal smoking and breastfeeding and maternal obesity and breastfeeding are similar: increasing levels of smoking or obesity are associated with shorter duration of breastfeeding. However, maternal infant feeding intention is a strong predictor of breastfeeding duration.
  
  
  OBJECTIVE
  In this paper we present data on another variable with a clear dose-response relationship with breastfeeding duration--maternal diet--as a case study to argue that a dose-response relationship does not imply causality.
  
  
  METHODS
  Secondary analysis of cross-sectional survey.
  
  
  METHODS
  Nationally representative sample of 3544 singleton infants in Longitudinal Study of Australian Children, 2004.
  
  
  METHODS
  Maternal intake of fruit and vegetables; breastfeeding duration.
  
  
  RESULTS
  Adjusted Odds Ratios (AOR) for breastfeeding at 6 months for daily maternal fruit and vegetable intake (reference group=no fruit/vegetables): 1 serve AOR 1.6 (95%CI 1.0, 2.6); 2 serves AOR 2.3 (1.5, 3.5); and 6 or more serves AOR 4.4 (2.8, 6.8).
  
  
  CONCLUSIONS
  Although higher maternal intake of fruit/vegetables is associated with longer breastfeeding duration, this is not a biological causal relationship. There are possible biological explanations for altered milk supply in women who smoke or are obese, but not for fruit/vegetable intake. We call for a broader understanding of the social determinants of infant feeding and suggest that all breastfeeding studies measure maternal infant feeding intention as an important determinant.
authors: Mother & Child Health Research, La Trobe University, Melbourne, VIC, Australia. l.amir@latrobe.edu.au
authors: Lisa H
authors: LH
authors: Amir
authors: Susan M
authors: SM
authors: Donath
mesh_terms: D000293:Adolescent; D000328:Adult; D001942:Breast Feeding; D002675:Child, Preschool; D002755:Choice Behavior / Q000502:physiology; D003430:Cross-Sectional Studies; D004032:Diet; D004034:Diet Surveys; D005247:Feeding Behavior / Q000502:physiology; D005260:Female; D005638:Fruit; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male; D008425:Maternal Behavior / Q000502:physiology*; D039382:Maternal Nutritional Physiological Phenomena / Q000502:physiology*; D011247:Pregnancy; D013850:Thinking / Q000502:physiology; D014675:Vegetables; D055815:Young Adult