Breastfeeding for four months or more is associated with fewer behavioural problems in children at age 5, an Oxford University study suggests.
The findings, published in the journal Archives of Disease in Childhood, add to the evidence base on the benefits of breastfeeding.
‘Our results provide even more evidence for the benefits of breastfeeding,’ says Maria Quigley of the National Perinatal Epidemiology Unit at Oxford University, who led the work with Katriina Heikkilä.
‘Mothers who want to breastfeed should be given all the support they need. Many women struggle to breastfeed for as long as they might otherwise like, and many don’t receive the support that might make a difference.’
There are a number of well-known health benefits of breastfeeding: for example, breastfed babies have lower rates of infections and mothers have a reduced risk of breast cancer. A range of other health and child development benefits have also been suggested – such as higher IQ, fewer behavioural problems and lower levels of obesity – but the evidence for these can be inconsistent across different studies.
The researchers from the University of Oxford, along with colleagues from the University of Essex, University College London and the University of York, set out to investigate associations between the duration of any breastfeeding and child behaviour at age 5.
‘We found that children who were breastfed for at least four months were less likely to have behavioural problems at age 5,’ says Maria Quigley.
‘However, that observation might not have been the direct result of breastfeeding – it could have been down to a number of factors,’ she explains. ‘As a group, mothers who breastfed for four months were very different socially to those who formula fed. They were more likely to be older, better educated and in a higher socio-economic position, on average.
‘Having controlled for these and other differences between the groups, we found there was still a 30% lower risk of behaviour problems associated with prolonged breastfeeding.’
The team used a nationwide survey of infants born in a 12-month period in 2000–2001 called the Millennium Cohort Study. This cohort study, for which the data are openly available, involved carrying out home interviews with parents when their children were 9 months old, with further follow-up interviews roughly every two years.
The Oxford researchers included data for over 9,500 mothers and babies born at full term to families of white ethnic background. They used answers from the initial interview when the children were 9 months old to determine whether mothers had breastfed and how long for.