But many factors determine IQ, not just mother's milk
WebMD News from HealthDay
By Steven Reinberg
TUESDAY, March 17, 2015 (HealthDay News) -- Breast-fed babies may be smarter, better educated and richer as adults, a new study by Brazilian researchers suggests.
"Breast-feeding is associated with improved performance in intelligence tests at age 30 and also has an important effect on a societal level by increasing educational attainment and income in adulthood," said lead researcher Dr. Bernardo Horta, of the Federal University of Pelotas.
"Taking into consideration these long-term benefits of breast-feeding as well as its short-term consequences, it is important to get more women to breast-feed their infants," he added.
The study was published March 17 in The Lancet Global Health.
However, one baby doctor not involved with the study said it's impossible to prove that breast-fed babies grow up to be smarter, more successful adults.
And Erik Mortensen, author of an accompanying journal editorial who's with the department of public health at the University of Copenhagen in Denmark, said the study only shows an association between breast-feeding and IQ, not proof of cause and effect.
But the link is very strong, Mortensen said. "It may not be a causal effect, but in my judgment, the overall evidence from other studies and the Brazilian study suggests that the effects are causal," he said.
Still, it's important for women to know that breast-feeding does not determine destiny, Mortensen added.
"Breast-feeding is only one of many factors which influence the development of intelligence. And it actually appears that factors such as parental intelligence, parental education and social class have a stronger influence on the development of offspring intelligence," he said.
For the study, Horta's team collected decades of data on nearly 3,500 infants born in 1982 in Pelotas, Brazil. The data included information on breast-feeding, as well as education, income and standard IQ test results at age 30.
The researchers found that infants who were breast-fed had higher IQs, more years of school and higher incomes as adults than those who weren't breast-fed. Moreover, the longer a baby was breast-fed -- up to a year -- the greater these benefits, the researchers said.
source : Breast-Fed Babies May Be Smarter, Richer Adults, Study Suggests