Breastfed kids 'are smarter'
2008-05-06 07:28
Montreal - Mothers who breastfeed their children can expect them to grow up smarter than their formula-fed peers, say Canadian researchers in the largest ever study of lactation, released on Monday.
The study published in this month's issue of Archives of General Psychiatry found that breastfeeding raises a child's IQ and improves his or her academic performance.
"Our study provides the strongest evidence to date that prolonged and exclusive breastfeeding makes kids smarter," said lead investigator Michaelo Kramer, of McGill University in Montreal.
His team followed 13 889 infants born between June 1996 and December 1997 at 31 Belarussian maternity hospitals and clinics for 6.5 years.
Half of the mothers were encouraged to breastfeed exclusively and for a prolonged period, while the other half were not.
The children's cognitive abilities were later assessed using IQ tests and based on their early grades at school.
On average, the breastfed group scored better in all tests, and "significantly higher" in both reading and writing.
Kramer said, however, that it is still unclear if the cognitive benefits of breastfeeding are due to the makeup of breast milk itself or the social and physical interactions between mother and child inherent in breastfeeding.
In the study, he suggests that the higher frequency and duration of breastfeeding compared to bottle-feeding results in increased verbal interaction between mother and child, which "might also have a stimulatory effect on cognitive development".
Other studies, he also points out, have shown that a mother rat's grooming and licking of its pups has long-term behavioural effects on its offspring.