title: Protective effect of breast feeding against infection.
abstract: OBJECTIVE
  To assess the relations between breast feeding and infant illness in the first two years of life with particular reference to gastrointestinal disease.
  
  
  METHODS
  Prospective observational study of mothers and babies followed up for 24 months after birth.
  
  
  METHODS
  Community setting in Dundee.
  
  
  METHODS
  750 pairs of mothers and infants, 76 of whom were excluded because the babies were preterm (less than 38 weeks), low birth weight (less than 2500 g), or treated in special care for more than 48 hours. Of the remaining cohort of 674, 618 were followed up for two years.
  
  
  METHODS
  Detailed observations of infant feeding and illness were made at two weeks, and one, two, three, four, five, six, nine, 12, 15, 18, 21, and 24 months by health visitors.
  
  
  METHODS
  The prevalence of gastrointestinal disease in infants during follow up.
  
  
  RESULTS
  After confounding variables were corrected for babies who were breast fed for 13 weeks or more (227) had significantly less gastrointestinal illness than those who were bottle fed from birth (267) at ages 0-13 weeks (p less than 0.01; 95% confidence interval for reduction in incidence 6.6% to 16.8%), 14-26 weeks (p less than 0.01), 27-39 weeks (p less than 0.05), and 40-52 weeks (p less than 0.05). This reduction in illness was found whether or not supplements were introduced before 13 weeks, was maintained beyond the period of breast feeding itself, and was accompanied by a reduction in the rate of hospital admission. By contrast, babies who were breast fed for less than 13 weeks (180) had rates of gastrointestinal illness similar to those observed in bottle fed babies. Smaller reductions in the rates of respiratory illness were observed at ages 0-13 and 40-52 weeks (p less than 0.05) in babies who were breast fed for more than 13 weeks. There was no consistent protective effect of breast feeding against ear, eye, mouth, or skin infections, infantile colic, eczema, or nappy rash.
  
  
  CONCLUSIONS
  Breast feeding during the first 13 weeks of life confers protection against gastrointestinal illness that persists beyond the period of breast feeding itself.
authors.affiliation: Ninewells Hospital and Medical School, Dundee.
authors.forename: P W
authors.initials: PW
authors.lastname: Howie
authors.forename: J S
authors.initials: JS
authors.lastname: Forsyth
authors.forename: S A
authors.initials: SA
authors.lastname: Ogston
authors.forename: A
authors.initials: A
authors.lastname: Clark
authors.forename: C D
authors.initials: CD
authors.lastname: Florey
mesh_terms: D001903:Bottle Feeding; D001942:Breast Feeding; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D005767:Gastrointestinal Diseases / Q000453:epidemiology / Q000517:prevention & control; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D017053:Infection Control; D007239:Infections / Q000453:epidemiology; D008423:Maternal Age; D011446:Prospective Studies; D012044:Regression Analysis; D012606:Scotland / Q000453:epidemiology; D013997:Time Factors