Association between breast feeding and asthma in 6 year old children: findings of a prospective birth cohort study.
OBJECTIVE
To investigate the association between the duration of exclusive breast feeding and the development of asthma related outcomes in children at age 6 years.


METHODS
Prospective cohort study.


METHODS
Western Australia.


METHODS
2187 children ascertained through antenatal clinics at the major tertiary obstetric hospital in Perth and followed to age 6 years.


METHODS
Unconditional logistic regression to model the association between duration of exclusive breast feeding and outcomes related to asthma or atopy at 6 years of age, allowing for several important confounders: sex, gestational age, smoking in the household, and early childcare.


RESULTS
After adjustment for confounders, the introduction of milk other than breast milk before 4 months of age was a significant risk factor for all asthma and atopy related outcomes in children aged 6 years: asthma diagnosed by a doctor (odds ratio 1.25, 95% confidence interval 1.02 to 1.52); wheeze three or more times since 1 year of age (1.41, 1.14 to 1.76); wheeze in the past year (1.31, 1.05 to 1.64); sleep disturbance due to wheeze within the past year (1.42, 1.07 to 1.89); age when doctor diagnosed asthma (hazard ratio 1.22, 1.03 to 1.43); age at first wheeze (1.36, 1.17 to 1.59); and positive skin prick test reaction to at least one common aeroallergen (1.30, 1.04 to 1.61).


CONCLUSIONS
A significant reduction in the risk of childhood asthma at age 6 years occurs if exclusive breast feeding is continued for at least the 4 months after birth. These findings are important for our understanding of the cause of childhood asthma and suggest that public health interventions to optimise breast feeding may help to reduce the community burden of childhood asthma and its associated traits.
Oddy
W H
WH
TVW Telethon Institute for Child Health Research, West Perth, Western Australia, Australia 6872.
Holt
P G
PG
Sly
P D
PD
Read
A W
AW
Landau
L I
LI
Stanley
F J
FJ
Kendall
G E
GE
Burton
P R
PR
D017677:Age Distribution; D017668:Age of Onset; D001249:Asthma / Q000453:epidemiology* / Q000209:etiology; D001942:Breast Feeding; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005865:Gestational Age; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011446:Prospective Studies; D012307:Risk Factors; D017678:Sex Distribution; D011795:Surveys and Questionnaires; D016019:Survival Analysis; D014904:Western Australia / Q000453:epidemiology