Protective effect of breast feeding against infection

BMJ. 1990 Jan 6;300(6716):11-6. doi: 10.1136/bmj.300.6716.11.


Objective: To assess the relations between breast feeding and infant illness in the first two years of life with particular reference to gastrointestinal disease.

Design: Prospective observational study of mothers and babies followed up for 24 months after birth.

Setting: Community setting in Dundee.

Patients: 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.

Interventions: 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.

Main outcome measure: 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.

Conclusion: Breast feeding during the first 13 weeks of life confers protection against gastrointestinal illness that persists beyond the period of breast feeding itself.

PIP: The hypothesis that breastfeeding has a protective effect on the incidence of childhood illnesses in the 1st 2 years of life, particularly gastrointestinal disease, was investigated in a prospective study of 618 Scottish infants. Detailed observations of infant feeding practices and sickness episodes were made at 2 weeks and 1, 2, 3, 4, 5, 6, 9, 12, 15, 18, 21, and 24 months of age by health visitors. Of the 674 mother-infant pairs originally enrolled in the study, 267 bottle-fed from birth, 180 breastfed but weaned before their infant was 13 weeks of age, and 227 breastfed for 13 weeks or more (97 of these women exclusively breastfed their infants for the 1st 13 weeks of life). During the 1st 13 weeks, the adjusted rate (corrected for social class, maternal age, and parental smoking) for gastrointestinal illness was 2.9% among fully breastfed and 5.1% among partially breastfed infants compared with 15.7% among bottle-fed infants and 16.7% among weaned infants. In addition, the rate of respiratory illness was significantly greater in bottle-fed infants (37.0%) compared with partially (24.2%) and fully (25.6%) breastfed infants. In the period beyond the 1st 13 weeks of life, infants who had been partially or fully breastfed initially had significantly lower rates of gastrointestinal disease at 14-26 weeks, 27-39 weeks, and 40-52 weeks compared to bottle-fed infants and a lower rate of hospital admission. Although brief breastfeeding (less than 13 weeks) did not confer significant protection against disease, infants who were breastfed 13-26 weeks had as much subsequent protection as those breastfed for longer durations.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bottle Feeding
  • Breast Feeding*
  • Confidence Intervals
  • Female
  • Follow-Up Studies
  • Gastrointestinal Diseases / epidemiology
  • Gastrointestinal Diseases / prevention & control
  • Humans
  • Infant
  • Infant, Newborn
  • Infection Control*
  • Infections / epidemiology
  • Maternal Age
  • Prospective Studies
  • Regression Analysis
  • Scotland / epidemiology
  • Time Factors