Breastfeeding and timing of first dietary introduction in relation to childhood asthma, allergies, and airway diseases: A cross-sectional study

ABSTRACT

Objectives: We investigated associations of breastfeeding (BF) durations and patterns and of timing of other dietary introductions with prevalence of asthma, wheeze, hay fever, rhinitis, pneumonia, and eczema among preschool children. Methods: During April 2011-April 2012, we conducted a cross-sectional study in 72 kindergartens from five districts of Shanghai, China and obtained 13,335 questionnaires of children 4–6-years-old. We used multiple logistic regression models to evaluate the target associations. Results: Compared to children who were never BF, children who were exclusively breastfed 3–6 months had the lowest risk of asthma (adjusted odds ratio and 95% confidence interval: 0.81, 0.72–0.91) and wheeze (0.93, 0.87–0.99); and exclusive BF >6 months was significantly associated with a reduced risk of hay fever (0.93, 0.89–0.97), rhinitis (0.97, 0.94–0.99), pneumonia (0.97, 0.94–0.99), and eczema (0.96, 0.93–0.99). No significant associations were found between time when fruits or vegetables were introduced and the studied diseases. Associations were independent of the child's sex and parent's ownership of the current residence. Longer duration BF was only significantly protective when there was no family history of atopy. Conclusions: This study suggests that heredity, but not sex and socioeconomic status, may negatively impact the effect of BF on childhood airway and allergic diseases. Our findings support China's national recommendation that mothers provide exclusive BF for the first four months, and continue partial BF for more than 6 months.

KEYWORDS:

• Allergy
• breastfeeding
• China
• pneumonia
• preschool children

Acknowledgements

The authors thank the Shanghai Municipal and District Bureau of Education for their supports, and greatly appreciate the work of Prof. Yinping Zhang (Tsinghua University), Prof. Baizhan Li (Chongqing University), and Dr. Yuexia Sun (Tianjin University) in preparing the questionnaire, and Dr. Zhuohui Zhao (Fudan University) for obtaining the ethical approval for CCHH project, and we express our thanks to all who participated in the survey.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the article.

Funding

This study was financially supported by National Natural Science Foundation of China (51278302), Innovation Program of Shanghai Municipal Education Commission (14ZZ132), Hujiang Foundation of China (D14003), and the Innovation Fund Project for Graduate Student of Shanghai (JWCXSL1401). The funder provided support in the form of salaries for authors, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of the authors are articulated in the authors' contributions' section.