The study suggests that breastfeeding could reduce the number of infants who go on to develop asthma, coeliac disease or obesity by almost 50,000 a year.

Previous studies on breastfeeding have all been reported in measures of relative risk or odds ratio. But this form of statistical analysis does not give a clear indication of the burden of the risk factor on the population, say researchers from Manchester.

For the latest study, they used a measure called the ‘population impact number' to assess the impact of failure to breastfeed on a child's health.

This technique calculates the potential number of disease events prevented in a population over a period of time by eliminating a risk factor.

For this study, data on breastfeeding and prevalence of chronic conditions were used to calculate the population impact of breastfeeding on asthma, coeliac disease and obesity.

The researchers focused on the impact of breastfeeding on the 596,122 infants born in England and Wales in 2002.

This suggested that if all babies had been breastfed, 33,100 cases of asthma, 2,655 cases of coeliac disease and 13,639 cases of obesity could have been prevented over the following seven to nine years.

Lead researcher Dr Anthony Akobeng, from the department of paediatric gastroenterology at Booth Hall Children's Hospital, Manchester, said that using population impact numbers could allow the impact of breastfeeding to be quantified and communicated in a way that will make it easier for both the public and decision makers to understand.

‘Many of the epidemiological measures used to report risk, such as relative risk and odds ratio, may indicate how strongly exposure and disease are associated with not breastfeeding, but do not indicate directly the benefits to the population.'

sanjay.tanday@haymarket.com

Arch Dis Child 2007; 92: 483-485