The introduction of milk other than mother's milk too early in infancy may increase the risk of developing asthma, a new Professor at the University of Leicester claims.
Children who are exclusively breast fed for at least the first four months are less prone to developing asthma or related ill health, a study involving Professor Paul Burton discovered.
Professor Burton, Professor of Genetic Epidemiology at the University of Leicester, was involved in a study of over 2000 children in Perth, Australia, where he was formerly Head of Biostatistics and Genetic Epidemiology at the TVW Telethon Institute for Child Health Research.
The study, published in the British Medical Journal today (Friday September 24) found:
Professor Burton and co-authors of the study said: "There is a significant reduction in the risk of childhood asthma at age six years if exclusive breast-feeding is continued for at least the first four months of life. These findings are important for our understanding of the aetiology of childhood asthma, and suggest that public health interventions to optimise breast feeding practices may help to reduce the community burden of childhood asthma and its associated traits."
The authors added that asthma is the leading cause of admission to hospital in Australian children and its prevalence is increasing. Susceptibility to asthma may be increased by factors present in early life - being male, low birth weight, preterm birth, young maternal age, maternal smoking and, the study now suggests, the early cessation of exclusive breast feeding.
Professor Burton and his co-authors state in their report: "Our study provides evidence consistent with others of a protective effect of exclusive breast feeding against a range of end points reflecting asthma and atopy.
Consistent with other studies, we found that it was the age that other milk was introduced rather than the duration of breast feeding that was more closely associated with asthma or atopy at age 6 years. This favours "exclusion" mechanisms. The two variables are, however, strongly correlated, and we cannot definitively reject the possibility that it is breast feeding itself that is of prime importance.
"Delaying the introduction of milk other than breast milk until at least 4 months of age may protect against asthma and atopy later in childhood. These findings are relevant to our understanding of the cause of childhood asthma and also to public health. Although further studies and analyses are required to confirm these benefits and to understand better the mechanisms concerned, public health interventions promoting an increased duration of exclusive breast feeding may help to reduce the morbidity and prevalence of childhood asthma."
An earlier study carried out at the University of Leicester found asthma levels in under-fives have doubled within a decade. The study, involving a group from the Department of Child Health and the Fosse Health Trust found a doubling of both reported wheeze and a diagnosis of asthma amongst children under the age of five, over the last eight years.
NOTE TO NEWSDESKS: FOR MORE INFORMATION PLEASE CONTACT PROFESSOR BURTON ON 0116 252 5445 (Secretary, Becky Anderton 0116 252 3156).
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