Add increased intelligence to the list of benefits associated with breastfeeding.
According to researchers
, children who were breastfed longer had higher scores on intelligence or IQ tests.
Using standardized tests, researchers at Boston Children’s Hospital in Massachusetts measured the IQ of some 1,300 children whose mothers were enrolled in a long-term study that looked for ways to improve maternal and child health.
Investigators tested the youngsters at age 3 to determine their ability to understand language. Lead researcher Mandy Brown Belfort says aptitude was an average of 2.5 percent higher among children who received nothing but breast milk for the first year, compared to infants who were given formula.
“And then at age 7, we looked at verbal and non-verbal IQ and there the effect was a little bit stronger. So, for each additional month of breastfeeding, the IQ score was about a third of a point higher," said Belfort.
Belfort, a neonatologist at Boston Children’s and professor of pediatrics at Harvard Medical School, says breastfeeding was not associated with higher scores on a test that measured memory and learning.
However, researchers found that visual motor skills, or the ability of the eyes to guide movements, were better among 3 year olds whose mothers consumed two or more servings of fish per week.
At this point, Belfort says investigators can only speculate as to the reasons why breastfed children had higher IQs.
“One is that there are either nutrients or other substances in breast milk that benefit the developing brain but haven’t been discovered yet, and so aren’t being added routinely to infant formula," she said.
Another possible explanation for the effect of breastfeeding duration on IQ, according to Belfort, is there is something about the interaction between mother and baby that boosts the child’s intelligence.
A study on the link between the length of breastfeeding and IQ in children is published in the journal JAMA Pediatrics.