Duration of breastfeeding, age at introduction of complementary foods and allergy-related diseases: a prospective cohort study

Abstract

Background The influences of breastfeeding and infant diet in the prevention of allergy-related diseases are uncertain and many of the studies conducted on the topic are limited by methodological challenges. Our aim was to assess whether the duration of breastfeeding and age at complementary food introduction affected the prevalence of asthma, wheeze, allergic rhinoconjunctivitis (ARC) and eczema at two and six years of age. Methods We used information gathered between 2000 and 2014 through questionnaires in the Prevention of Allergy among Children in Trondheim (PACT) study, a prospective cohort study in Trondheim, Norway. The current study includes 6802 children who submitted questionnaires detailing breastfeeding duration and or age at introduction to complementary foods, as well as at least one of the child health questionnaires completed at two and six years of age. Adjusted odds ratios (aORs) were calculated for each combination of exposure and outcomes and sensitivity analyses were performed to assess the possible influence of recall bias and reverse causality. Results The mean duration of breastfeeding was 11 months (SD 5.6) in this study population and 5695 of 6796 (84%) infants had been breastfed for at least 6 months. We did not find any conclusive preventative effect of longer breastfeeding on parental reported doctor-diagnosed asthma, aOR 0.79 (95% CI 0.51, 1.21). However, at 6 years of age we observed a reduction in the less strictly defined outcome wheeze, aOR 0.71 (95% CI 0.53, 0.95). Longer breastfeeding was associated with a reduced risk of ARC at 2 years, aOR 0.65 (95% CI 0.49, 0.86), with a continued protective trend at 6 years, aOR 0.77 (95% CI 0.58, 1.04). Conclusions Longer breastfeeding resulted in a reduced risk of wheeze and a trend towards a protective effect on ARC up until school age. No conclusive associations were seen between the duration of breastfeeding or age at introduction to complementary foods and prevention of asthma, wheeze, ARC and eczema. Trial registration The trial is registered in Current Controlled Trials as ISRCTN28090297.

Prolonged breastfeeding and protective effects against the development of allergic rhinitis: a systematic review and meta-analysis

“…There were four studies that included specific populations: one study assessed rhinitis population (12) , two studies assessed population with HLA-conferred susceptibility to type 1 diabetes (29,33) , and one study assessed population with maternal history of asthma which was considered as a high-risk for developing AR (30) . The ISAAC questionnaire was the most common epidemiological tool for diagnosing AR used in 18 studies (6,(27)(28)(29)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42)44,46) . A skin prick test was used to define AR in three studies (12,30,38) .…”

“…Atopic sensitization was investigated by specific IgE tests in nine studies (6,12,27,(29)(30)(31)34,38,46) . Seventeen out of 23 studies had adequate adjustment for confounding variables (6,12,27,28,(30)(31)(32)(33)(34)(35)(36)(40)(41)(42)(43)(44)46) .…”

“…Eighteen studies assessed the effect of prolonged nonexclusive breastfeeding (≥6 months) (6,12,26,28,29,(31)(32)(33)(34)(35)(36)(39)(40)(41)(42)(43)(44)46) . One study (33) used hazard ratio (HR) and found no association with the risk of seasonal AR.…”

“…One hundred and nine studies were selected for full-text review. Twenty-three observational studies (nine cohort studies (6,(26)(27)(28)(29)(30)(31)(32)(33) and 14 crosssectional studies (12,(34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45)(46) ) were included for qualitative synthesis, of which 20 studies (12,(26)(27)(28)(30)(31)(32)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45)(46) were included in meta-analysis.…”

Impact of Using Social Marketing Principles on Promoting Breastfeeding Practices and Physical Growth: an Egyptian Community Based Longitudinal Study

“…Cultural factors were also reported by many studies in the Middle East countries; in which EBF's primary barriers were women's perceptions of insu cient breast-milk, beliefs about infant thirst, and need for water (41) or due to receiving con icting advice such as discouraging formula but encouraging herbal drinks (42). Meanwhile, in different societies around the world women's breastfeeding practices were commonly affected by others' comments resulting in introducing complementary foods before six months of age (42,43).…”