A provocative study from Brazil is reporting that breastfed babies have higher IQ and tend to have higher earnings in later life.
We are all familiar with the advantages of breastfeeding in the short-term, especially to the infant’s immune system, but, according to a study published this year in The Lancet, long-term results of breastfeeding had not been extensively studied. The study sought to determine whether the amount of time that a child is breastfed impacted IQ, years of schooling, and income at 30 years old. The study was carried out in Brazil where breastfeeding was not particularly common when the study began.
According to a lead researcher, speaking to NY Daily News, “What is unique about this study is the fact that, in the population we studied, breastfeeding was not more common among highly educated, high-income women, but was evenly distributed by social class.”
In order to study long-term benefits, the study, funded in part by the Brazilian Ministry of Health, began with a group of infants born in 1982. Information on breastfeeding history was recorded while the participants were still infants. Available participants were then reviewed at age 30 for IQ (using Wechsler Adult Intelligence Scale, 3rd version), educational level, and income.
Researchers were able to gather adult data from 3493 of the original 5914 infants. Their analyses showed that the durations of total breastfeeding and predominant breastfeeding (the time when breastfeeding is the main form of nutrition) were positively associated with all three factors. Children who were breastfed longer and more exclusively attained higher IQ, education, and income.
According to Forbes, the study is particularly interesting because the benefits were seen across all socioeconomic strata, suggesting that this benefit is available to everyone.
Researchers postulate that the benefits are due to long-chain fatty acids in breast milk, which are so important for a developing brain.
“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,” said study author Bernardo Lessa Horta.
Participants who breastfed for 12 months or more had a difference of 3·76 points in IQ, .91 years more education, and higher monthly incomes (341 Brazilian Reals or $104). The analysis suggests that IQ was responsible for 72% of the effect on income.