PARIS - People breastfed as infants have higher intelligence scores in adulthood and higher earnings, according to a study that tracked the development of about 3,500 newborn babies over 30 years. And, critically, the socio-economic status of mothers appeared to have little impact on breastfeeding results, according to a paper published by The
Lancet medical journal yesterday.
"The effect of breastfeeding on brain development and child intelligence is well established," lead author Bernardo Lessa Horta of the Federal University of Pelotas in Brazil said in a statement.
What has been less clear is whether the effects persist into adulthood, and whether a mother's socio-economic status or education level played a bigger role in the outcome of previous studies than her choice to breastfeed or not.
"Our study provides the first evidence that prolonged breastfeeding not only increases intelligence until at least the age of 30, but also has an impact both at an individual and societal level by improving educational attainment and earning ability," said Dr Horta..
Information on breastfeeding was compared with IQ test results at the average age of 30 years, as well as the educational achievement and income level of the 3,493 participants.
"While the study showed increased adult intelligence, longer schooling and higher adult earnings at all duration levels of breastfeeding, the longer a child was breastfed for (up to 12 months), the greater the magnitude of the benefits."
A person breastfed for at least a year as a baby gained a full four IQ points, had 0.9 years more schooling, and an income of 341 Brazilian reals (S$145) higher a month at the age of 30, compared with those breastfed for less than one month, the study found.
"The likely mechanism underlying the beneficial effects of breast milk on intelligence is the presence of long-chain saturated fatty acids found in breast milk, which are essential for brain development," said Dr Horta.
The findings also suggest that the amount of milk consumed plays a role, he noted.