It’s become a hot-nipple topic for every first-time Mom: Will breastfeeding boost my child’s intelligence? A spate of scientific studies conducted over the past decade have strongly suggested as much.
According to a meta-analysis of 17 such studies conducted in 2015, breastfed children demonstrated slightly higher cognitive abilities – an average of 4-7 points on IQ tests. Other studies have shown that breast-feeding makes newborns less susceptible to infections and lowers the risk of diabetes and cancer in adulthood.
It may not create an Einstein, but the case for breastfeeding – a subject of ongoing scientific and public controversy – would seem to be a slam-dunk.
But it’s not. In fact, some of the most recent breastfeeding studies have largely debunked the intelligence claim. In 2017, researchers led by Dr. Lisa-Christine Girard of the University of Dublin School of Public Health, Physiotherapy and Sports Science, found no causal link between breast-feeding and cognitive outcomes, including problem-solving and vocabulary use. Their results, first published in the journal Pediatrics in April 2017, have stunned many breastfeeding advocates.
Girard’s study was unusually robust. She and her team drew on a sample of 8,000 mothers who had participated in a larger longitudinal study – “Growing Up in Ireland.” The children were tested using psychometric scales at age 3 and again at age 5 to assess their cognitive and emotional development. The team supplemented its statistical findings with in-person interviews with a sub-sample of parents and teachers to gain greater insight into individual cases.
Girard’s team was hoping to find a causal link of some kind between breast-feeding and intelligence – but they came up empty. It turns out that even prolonged breastfeeding of children well beyond the infant stage has no appreciable effect. The one positive impact the study found was for a reduction in hyperactivity – but even this effect turned out to be weak. By age 5, there was no statistically significant difference in the level of hyperactivity between children who were breastfed and those that drank artificial bottled milk.
Why did researchers once find what appeared to be a direct causal link between breastfeeding and intelligence? Because it turns out that mothers with higher IQ’s – a factor that tends to correlate with higher education and incomes — are more likely to breast-feed; as a result, they naturally pass on their intelligence genes to their children. In the Ireland study, Girard initially found some evidence of a link between breastfeeding and intellect – that is, until they controlled for income. Only higher-income women’s breastfeeding seemed to matter, in fact.
But upon closer examination, even this widely shared conclusion turns out to be tenuous. Studies have compared siblings, one that was breast-fed and another than was not, and found no cognitive advantage in the one that was breast-fed. Clearly, even if there might be a causal link of some kind between the intelligence of parents and their kids’ – it is likely just genetic, plus the likely positive effects of their more supportive home and school environments.
Upshot? There may be smarty parents — but there are no smarty-boobs.
That doesn’t mean that breastfeeding is a bad idea, of course — for the reasons already cited. But the more one looks at the issue, the more skeptical one becomes that feeding a baby with a bottle is something some mothers should feel especially guilty about. Other studies have shown that children that are fed both ways gain the same health advantages as those fed by breast milk alone. And their moms don’t have to worry about the wear and tear to their breasts or brave the stares and glares of strangers while they breast-feed in public
Don’t first-time mothers have enough to worry about without having to choose sides in today’s “Mommy Wars”? Breast-feed if you want – or bottle feed if you don’t. Besides, whatever the scientific evidence, are a handful of IQ points really worth fighting over?