Breastfeeding exclusively or for a prolonged period does not protect children against developing asthma and allergies, according to the results of a large randomised trial published on bmj.com today.
Whether breastfeeding protects against the development of allergies and asthma has been the subject of numerous studies and a topic of hot debate for the past 70 years. Yet research findings have been conflicting and all the evidence to date has been based on observational studies.
In this study researchers recruited 17,046 breastfeeding women attending 31 Belarussian maternity hospitals and one polyclinic affiliated with each maternity hospital during the late 1990s. They were split into two groups. In the experimental group breastfeeding was promoted and supported in the hospitals and polyclinics the women and children attended. In the control group the hospitals and clinics continued with their normal practices and policies. Within the experimental group there was a large increase in the number of women breastfeeding exclusively at three months. The women in this group also breastfed for longer.
13,889 children were followed up when they reached 6.5 years of age and tested to see if they showed any symptoms of asthma or allergies. This research was carried out between December 2002 and April 2005. A questionnaire was used to diagnose asthma, hay fever, and eczema. In addition skin prick tests were used to diagnose sensitivity to house dust mites, cats, birch pollen, mold, and mixed northern grasses.
The results indicate that increased breastfeeding did not reduce the risk of asthma, hayfever or eczema at 6.5 years of age despite large increases in the duration and exclusivity of breastfeeding. It also did not succeed in reducing the prevalence of positive skin prick tests.
The researchers conclude that public health measures to increase breastfeeding seem unlikely to have a major impact on reducing the level of hereditary conditions such as asthma or eczema within the population.
They say: "our results underline the importance of seeking other explanations for the recent epidemic of allergy and asthma."