New research suggests breastfeeding your child for a longer duration could give them a higher IQ and help them earn more money later in life.
A team of researchers followed a group of almost 3,500 newborns for 30 years, and found a link between longer durations of breastfeeding and increased intelligence, the Lancet reported.
"Our study provides the first evidence that prolonged breastfeeding not only increases intelligence until at least the age of 30 years but also has an impact both at an individual and societal level by improving educational attainment and earning ability," said lead author Bernardo Lessa Horta from the Federal University of Pelotas in Brazil.
The study was unique because the likelihood of breastfeeding was distributed evenly across the participants by social class. Past studies have been criticized for not taking into account the link between breastfeeding and socioeconomic advantage.
To make their findings, the team looked at about 6,000 infants born in Pelotas, Brazil in 1982. Information on breastfeeding was collected and the participants were given an IQ test. They also provided information on their career success and income at the age of 30. Complete information was available for 3,493 of these participants, and these individuals were split into five groups that were controlled for factors such as social and biological variables and based on the length of time they were breastfed as infants.
The study showed a higher adult intelligence, longer schooling, and higher earnings at all durations of breastfeeding, but the longer a child was breastfed, the greater the benefits. An infant who was breastfed for a year gained an average of four full IQ points, 0.9 more years of schooling, and higher income equivalent to about one third of the average income level, compared to those breastfed for less than one month.
"The likely mechanism underlying the beneficial effects of breast milk on intelligence is the presence of long-chain saturated fatty acids (DHAs) found in breast milk, which are essential for brain development. Our finding that predominant breastfeeding is positively related to IQ in adulthood also suggests that the amount of milk consumed plays a role," Horta said.
The findings were published in a recent edition of the journal The Lancet Global Health.
