Most new moms believe their babies are geniuses. They may claim it's all thanks to good genes or special books or certain foods, but one thing's for sure: Their babies' smarts have nothing to do with whether or not they breastfeed, according to a September 2015 study published in PLOS ONE.
Researchers from Goldsmiths University of London examined data collected from more than 11,000 British children who were part of the Twins Early Development Study at King's College London. The kids' IQs were tested nine times over the course of 14 years, between the ages of 2 and 16.
After looking at the twins' data, the researchers concluded that breastfeeding was "not reliably related to IQ" by age 2, nor did it have an effect on IQ gains after a child's second birthday. And while the experts did report that the breastfed girls' IQs before the age of 7 were slightly higher than girls who weren't breastfed, the intelligence advantage "disappeared" by the time they turned 16.
"Mothers should be aware that they are not harming their child if they choose not to, or cannot, breastfeed," says Sophie von Stumm, PhD, study co-author and senior lecturer at Goldsmiths University of London. "Being bottle-fed as an infant won't cost your child a chance at a university degree later in life."
What's interesting is that this study directly contradicts several earlier studies that found breastfeeding is connected to a child's intelligence. Most recently, in March 2015, The Lancet Global Health published research that found an association between not only breastfeeding and increased intelligence, but also gaining a more advanced education and higher income as an adult.
But which study is right? It's worth noting that the Lancet research looked at only two IQ scores (once at 19 months and again at age 30) from each of the 3,500 participants, while the PLOS ONE study looked at nine IQ scores from each of the more than 11,000 twins, so the PLOS ONE study is much larger and uses more data points.
So Is Breast Always Best?
There's no denying the numerous health benefits of breastfeeding. Over the last year alone, medical experts have discovered or confirmed that a mother's milk can shape the baby's immune system for later in life, reduce common infections, better prepare a child for solid foods, protect the baby against environmental pollution and lower the risk of developing childhood leukemia.
"Multitudes of previous large studies indicate breastfeeding is good for both the mother's and baby's health, including intelligence," says Andrea Feigl, PhD, and Eric Ding, PhD, a husband-and-wife research team from the Harvard School of Public Health. "More should be said about the levels of different nutrients and different toxins in different breast milk, which changes over time and varies between individual and even within individuals. More should be answered regarding nutrition and toxins that children receive and likely affect cognitive development even more."
Draion "Dr. Drai" Burch, DO, a board-certified obstetrician and gynecologist, is also a firm believer in breastfeeding. "Giving your baby breast milk protects them against infections, protects them from developing allergies, may prevent obesity and may lower the risk of Sudden Infant Death Syndrome (SIDS)," he says.
But breastfeeding is not for everyone and may not even be possible for some women. And there's nothing wrong with that, adds Dr. Drai. "Yes, it's okay to give your baby formula," he says. "There's nothing to feel bad about, ladies. You aren't harming your child."