The study found that longer breastfeeding was associated with better education outcomes even when factors such as cognitive ability and socio-economic status were taken into account.
Children who were breastfed for longer were more likely to have a high pass in their English and Maths GCSEs and less likely to fail GCSE English (but not maths) when compared with children who were never breastfed.
Those who were breastfed for at least four months had, on average, a 2-3 point higher attainment 8 score and were more likely to pass five GCSEs.
Researchers at Oxford University looked at the association between breastfeeding duration and education outcomes at the end of secondary education.
Approximately 5,000 children from the Millennium Cohort Study - those born in 2000-2002 - in England were included in the analysis.
GCSEs are now graded 1-9 rather than the old system of U-A* with 9 being the top grade.
“A longer breastfeeding duration was associated with modest improvements in educational outcomes at age 16, after controlling for important confounders,” the study, published in Archives of Disease in Childhood journal, concluded.
Reneé Pereyra-Elías, from the Nuffield Department of Population Health, the lead author, said the results showed that breastfeeding should continue to be encouraged “when possible”.
She added that potential improvements in academic achievement were “only one” of the potential benefits of breastfeeding.
The study’s authors said there were “several” reasons why breastfed children performed better in their exams.
The main reason, they suggest, is breastfeeding improves “cognitive development”.
Breast milk contains polyunsaturated fatty acids and micronutrients, which enhance neurodevelopment.
“However, education may also be a marker of cognitive ability,” the study’s authors add
“Similarly, breastfeeding was associated with intergenerational upward social mobility (change in occupational social class) in the 1958 and 1970 British birth cohorts, and this effect was mediated by cognitive performance.”
It has also been proposed that breastfeeding may enable mother-child bonding, which would favour both cognitive and academic performance.
The NHS recommends that, mothers who are able to, should breastfeed their babies for six months before moving to a combination of breast milk and normal food.
Breastfeeding can also protect babies from diseases and infections and mothers from breast and ovarian cancer.
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