title: Duration of lactation and incidence of myocardial infarction in middle to late adulthood.
abstract: OBJECTIVE
  We assessed the relation between duration of lactation and maternal incident myocardial infarction.
  
  
  METHODS
  This was a prospective cohort study of 89,326 parous women in the Nurses' Health Study.
  
  
  RESULTS
  During 1,350,965 person-years of follow-up, 2540 cases of coronary heart disease were diagnosed. Compared with parous women who had never breastfed, women who had breastfed for a lifetime total of 2 years or longer had 37% lower risk of coronary heart disease (95% confidence interval, 23-49%; P for trend < .001), adjusting for age, parity, and stillbirth history. With additional adjustment for early-adult adiposity, parental history, and lifestyle factors, women who had breastfed for a lifetime total of 2 years or longer had a 23% lower risk of coronary heart disease (95% confidence interval, 6-38%; P for trend = .02) than women who had never breastfed.
  
  
  CONCLUSIONS
  In a large, prospective cohort, long duration of lactation was associated with a reduced risk of coronary heart disease.
authors.affiliation: Division of Maternal-Fetal Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA. astuebe@med.unc.edu
authors.forename: Alison M
authors.initials: AM
authors.lastname: Stuebe
authors.forename: Karin B
authors.initials: KB
authors.lastname: Michels
authors.forename: Walter C
authors.initials: WC
authors.lastname: Willett
authors.forename: JoAnn E
authors.initials: JE
authors.lastname: Manson
authors.forename: Kathryn
authors.initials: K
authors.lastname: Rexrode
authors.forename: Janet W
authors.initials: JW
authors.lastname: Rich-Edwards
mesh_terms: D000328:Adult; D000367:Age Factors; D001942:Breast Feeding; D003327:Coronary Disease / Q000453:epidemiology / Q000517:prevention & control; D005260:Female; D006801:Humans; D007774:Lactation / Q000502:physiology*; D009203:Myocardial Infarction / Q000453:epidemiology* / Q000517:prevention & control; D011247:Pregnancy; D011446:Prospective Studies; D013997:Time Factors