Sometimes it feels like a new study on raising smart kids is released every day. But a new research out of the Federal University of Pelotas in Brazil suggests that breastfeeding trumps all else when it comes to rearing a whip-smart child—resulting in adults who have higher IQs, are in school longer and earn more money. Lead study author Dr. Bernardo Lessa Horta published his findings in the April issue of The Lancet Global Health Journal.
"The effect of breastfeeding on brain development and child intelligence is well established, but whether these effects persist into adulthood is less clear," Dr. Horta says in an interview with Nicholai Humphreys on The Lancet Global Health podcast. "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."
Information on the duration of breastfeeding was collected from the parents of 5,914 Brazilian-born babies born in 1982. When the babies hit their 30s, they were given an IQ test and asked about their incomes and education achievements (however, data was only available for 3,493 of the 5,914). Other variables were also examined, including family income, birth weight, delivery type and maternal age. For babies breastfed for at least a year, researchers discovered that those adults scored four points higher on IQ tests, went to school 0.9 years longer and earned $100 more a month than those were were breastfed for less than a 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," Dr. Horta says. "Our finding that predominant breastfeeding is positively related to IQ in adulthood also suggests that the amount of milk consumed plays a role."
Now, despite the fact that I breastfed both my children well into toddlerhood—which would make them wealthy geniuses in 25 years—I'm skeptical of this study for two reasons:
I consider myself lucky to have been able to breastfeed my children successfully for as long as I did, but in no way do I attribute their intelligence to breast milk. Rather, it's thoughtful and intuitive parenting that oftentimes comes with trusting your gut and ignoring the latest research.