Children breastfed for at least a year were 38 per cent more likely to get a high pass – the equivalent of an A or A* – in their English GCSE exam, compared to children who were not breastfed, a study found.
These children were 39 per cent more likely to get the same top grade in their Maths GCSE.
Breast milk contains important polyunsaturated fatty acids, which are believed to boost brain development.
The study, involving almost 5,000 children in England, found those breastfed for at least four months were around 12 per cent more likely than non-breastfed children to pass at least five GCSEs, including English and Maths, with the equivalent of a low B or a high C grade.
Dr Reneé Pereyra-Elías, lead author of the study from the University of Oxford, said: ‘Better exam results appear to be another of the well-known benefits of breastfeeding, and so breastfeeding should be encouraged, but only where it is possible for women.
‘For those who are not able to breastfeed, they should not feel guilty and be worried about their child’s academic achievement, as the differences we saw in exam results associated with breastfeeding were not large.’
The study, published in the journal Archives of Disease in Childhood, looked at 4,940 children born between 2000 and 2002 who were part of the previous Millennium Cohort Study.
Almost a third of these children had never been breastfed, based on a survey of mothers which was part of the study.
The rest of the children were sorted into groups, based on how long they were breastfed, ranging from less than two months to more than a year.
The Oxford researchers analysed the GCSE results for these state school children, some of whom were graded from A* to F, but most of whom were given the new modern grading system from 1 to 9.
Children breastfed for at least a year were 25 per cent less likely to fail their English GCSE, with less than a 4, or the equivalent of a D or lower under the old system, compared to those not breastfed at all.
Researchers looked at children’s total score out of 90, based on the new grading system, for the eight highest GCSEs achieved by each pupil, with English and Maths double-counted, because they are a core part of the curriculum.
Children breastfed for longer than four months scored two to three points higher for this total GCSE score, compared to those never breastfed.
Some previous studies suggesting children breastfed for longer are more intelligent have faced criticism.
This is because they failed to take into account that children who are breastfed for longer tend to have more educated and well-off mothers, whose children may do better at school because of these advantages.
But the new research found a link between exam results and being breastfed even when accounting for parents’ socioeconomic position, based on their jobs and level of education.
It also took into account mothers’ intelligence, which was tested by giving women a vocabulary test of 20 words.
However the researchers note that the difference in exam results linked to whether teenagers were breastfed is ‘modest’, and they did not look at other factors including children’s family wealth directly, which could make a further difference to their achievement at school.
In general, children breastfed for longer did better in exams, although the strongest results were seen in those breastfed for longer than a year.
