BREAST-FEEDING REDUCES RISK OF RESPIRATORY ILLNESS IN INFANTS

Breastfeeding has long been believed to protect against infection in i nfants, but protection against respiratory illnesses has not been cons istently demonstrated in studies in developed countries. Between 1988 and 1992, the authors assessed the effect of breastfeeding on incidenc e and duration of respiratory illnesses during the first 6 months of l ife in a prospective study that actively tracked breastfeeding and res piratory illnesses, A cohort of 1,202 healthy infants, born in Albuque rque, New Mexico, between January 1, 1988 and June 30, 1990, from home s without smokers was enrolled. The daily occurrences of respiratory s ymptoms and breastfeeding status were reported by the mothers every 2 weeks. Illnesses were classified as lower respiratory illness (LRI) if wheezing or wet cough was reported; the remaining illnesses were clas sified as upper respiratory, The annualized incidence rates for LRI we re 2.8, 2.6, and 2.1 during follow-up time with no, partial, or full b reastfeeding, respectively, but the incidence rates for upper respirat ory illness and lower respiratory illness combined were similar in the three categories. After adjustment for potential confounding factors, full breastfeeding was associated with a reduction in lower respirato ry illness risk (odds ratio = 0.81, 95% confidence interval 0.68-0.96) , Median duration of all respiratory illnesses was 5 days for the full y breastfed infants during the first 6 months of life compared with a median of 6 days for not breastfed and partially breastfed infants. Mu ltivariate analysis confirmed that breastfeeding significantly reduced the duration of respiratory illness, This pattern of reduced incidenc e of LRI and shorter duration of all respiratory illnesses suggests th at breastfeeding reduces the severity of infant respiratory illnesses during the first 6 months of life.