A baby who lives on breast milk solely or for a long time does not have a lower risk of developing allergies or asthma compared to a baby who is not breast fed, says an article in the British Medical Journal (BMJ).

During the last seven decades the topic of breastfeeding, and whether it protects from asthma and/or allergies has been controversial and ardently debated, say the writers. However, the only evidence to date has been based on observational studies.

Researchers in this study recruited 17,046 breastfeeding mothers who attended 31 maternity hospitals attached to polyclinics in Belarus during the 1990s. The mothers were divided into two groups - one (experimental group) was encouraged to breastfeed, while in the other (control group) they were not. By the time the babies were three months old the number of mothers breastfeeding in the experimental group had increased substantially, compared to the control group. The researchers also reported that mothers in the experimental group continued breastfeeding for much longer.

6.5 years later 13,889 children were followed up and tested for symptoms of allergies and/or asthma. As not all the babies were born at the same time, the testing was carried out between December 2002 and April 2005. A questionnaire was also used to retrieve information on the diagnoses of eczema, hay fever and asthma. The 6.5 year-old children also underwent prick tests to measure their sensitivity to house dust mites, birch pollen, mold, cats, and mixed northern grass.

The scientists concluded that a 6.5 year-old child does not have a lower risk of developing asthma, hay fever or eczema if his/her breastfeeding was increased/introduced when he/she was a baby. Breastfeeding, say the writers, did not reduce the prevalence of positive skin prick tests for children aged 6.5 years (six-and-a-half years).

The authors added "our results underline the importance of seeking other explanations for the recent epidemic of allergy and asthma."

"Effect of prolonged and exclusive breast feeding on risk of allergy and asthma: cluster randomised trial"
Michael S Kramer, James McGill, Lidia Matush, Irina Vanilovich, Robert Platt, Natalia Bogdanovich, Zinaida Sevkovskaya, Irina Dzikovich, Gyorgy Shishko, Bruce Mazer
BMJ, doi:10.1136/bmj.39304.464016.AE (published 11 September 2007)
Click here to view abstract online