Associations between breast feeding and lung function in middle age

Abstract

<b>Background:</b> Breast feeding is associated with lung function in children and adolescents but evidence for its impact beyond adolescence is limited. <b>Objectives:</b> To investigate associations between breast feeding and lung function in middle age. <b>Methods:</b> We analysed data from 2598 participants followed from age 7 to 53 years in the Tasmanian Longitudinal Health Study, which collected information on breast feeding in the first three months as: exclusive (n=1129, 43.5%), mixed (n=811, 31.2%) or no breast feeding (n=658, 25.3%). Pre- and post- bronchodilator spirometry were measured at 53 years. Linear regression was used to investigate relationships between breast feeding and lung function, adjusting for age, sex, early life SES, maternal asthma, parental smoking, gestation and adult height. Potential effect modification by smoking and maternal asthma was investigated. <b>Results:</b> Compared to exclusive breast feeding, no breast feeding was associated with reduced FEV1 (Coefficient: -92 mL [95%CI: -165, -19]) and FVC (-102 mL [-189, -15]). There was evidence for an interaction between breast feeding and personal smoking with the deficits in lung function being greater among current smokers (for FEV1: -190 mL [-348, -33]; for FVC: -216 mL [-399, -33]) than never smokers (for FEV1: 25 mL [-72, 123]; for FVC: 38 mL [-75, 151]). Similarly, maternal asthma augmented the associations in the same negative direction. <b>Conclusions:</b> Non breast-fed babies may have lung function deficits in middle age, particularly if they later smoke or have a history of maternal asthma. This novel evidence can be used to further promote breast feeding, especially among new mothers with asthma.&nbsp;Smoking avoidance is critical for those who were not breast-fed.