New research has found no evidence that breastfeeding
boosts children’s intelligence or other cognitive abilities.

The findings, published in the journal Pediatrics , run contrary to previous studies on breastfeeding that found that it does boost intelligence.
The researchers from University College Dublin (UCD), led by
Dr Lisa-Christine Girard, analysed the effects of
breastfeeding on children’s cognitive abilities, such as
problem-solving and vocabulary, at ages three and five. They
also looked at the effects of hyperactivity in children who
breastfed.
The study involved 7,478 children at ages three and five who
participated in the Growing Up in Ireland longitudinal study of
children. The paper was published in the journal Pediatrics.
The investigators used a type of statistical analysis called
“propensity score matching” (PSM) that accounted for
certain factors that would make certain mothers more likely
to breastfeed, such as socioeconomic status and level of
education.
The researchers ensured the analysis separated the factors
that influence children’s development and intelligence from
breastfeeding itself.
Previous studies, for example, have shown that children from
families of lower socioeconomic status are less likely to be
breastfed.
By employing the PSM method, the researchers examined
two groups of children, from similar family backgrounds, that
were equally likely to be breastfed.
However, the children were divided into two groups – those
who had breastfed and those who hadn’t.
After accounting for the socioeconomic factors, the
scientists found that there was no statistically significant
evidence that children at ages three and five who were
breastfed as babies had gained more cognitive abilities than
children who were bottle-fed.
It is widely accepted that breastfeeding has many health
benefits for babies, such as protecting them from infection-
related deaths and sudden infant death syndrome.
The analysis found that only three-year-olds who had
breastfed for six months or more scored higher on tests of
problem-solving and lower on tests for hyperactivity.
But after accounting for the other factors, the researchers
found that the benefits for problem-solving between the two
groups were not statistically significant.
They found children who were breastfed for six months or
more had fewer problems with hyperactivity at the age of
three.
However, this positive outcome for three-year-olds
disappeared by the time they had reached the age of five.
No evidence was found that breastfeeding improved or
affected vocabulary at either age three or five.
The analysis also concluded that there were no statistically
significant cognitive benefits at all for children who breastfed
at the age of five.
Ireland has one of the lowest rates of breastfeeding in the
world. The Growing Up In Ireland study found that only 56
per cent of Irish mothers breastfed, compared to rates of
around 90 per cent elsewhere in Europe.