Here's what the data says about the breastfeeding vs. formula feeding debate
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Infant feeding has long been fertile ground for some of the internet’s sharpest “mommy wars." It can be enough to make any parent feel guilty and question their decisions — especially in the frazzled, sleep-deprived newborn days.
But what does the data say about breastfeeding and formula feeding? Is one choice really “best”? Yahoo Life spoke with Emily Oster, an economist, data-driven parenting guru and author of several books including The Family Firm, to shed some light on the infant feeding debate.
The data on breastfeeding
While there may be some advantages to breastfeeding early on, there isn’t much data to support the idea that breastfed babies are better off in the long run. One of the problems with information disseminated on the perks of breastfeeding, Oster explains, is that it often relies on correlation as opposed to a causal argument. For example, breastfeeding is often touted for its cognitive benefits because breastfed children tend to perform higher on IQ tests than non-breastfed children. But Oster says there isn’t enough evidence that breast milk is responsible for those higher test scores.
“Kids who were breastfed also tend to have moms with higher education; they tend to be from families with more resources; there are differences in the marital status of the parents,” Oster tells Yahoo Life. “And so when we say there are differeces in these kids based on whether they’re breastfed or not, it’s really hard to separate that from all the other differences which we know to be related to test scores.”
Oster says the best evidence of causal effects of breastfeeding occur early on, in the first weeks and months of a baby’s life. Breastfed infants may have lower incidence of gastrointestinal illnesses (such as diarrhea) and digestive issues and may be less likely to develop eczema and allergic rashes than formula-fed babies.
“But for kids, there’s really not anything in the data that’s strongly supported as a long-term benefit for breastfeeding,” Oster says.
The American Academy of Pediatrics (AAP) recommends exclusively breastfeeding for the first six months of a baby’s life, and recently released an updated policy statement extending the period of breastfeeding with solid foods to two years or more.
Oster points out that in this updated recommendation, the AAP only mentions benefits to the mother for breastfeeding two years or more. And while data has shown that breastfeeding moms may reap some longer-term benefits, including a lower risk of breast cancer, the evidence AAP cites on advantages of continuing to breastfeed beyond 12 months is a bit murkier.
“What they say is that there are potentially some benefits to mothers in terms of lower risks of diabetes, lower risks of heart disease later on,” Oster says of the updated AAP recommendations. “I dug into that data, and I think that their conclusions overstate what can be gleaned from that data. To give one concrete example, the evidence on Type 2 diabetes is based on looking at the total number of months that women breastfeed. But most women do not breastfeed a single child for more than a year. So actually, when you look at people who have breastfed in total for more than a year, most of those are people who [breastfed] multiple kids” over time.
In an email to Yahoo Life, Dr. Joan Younger Meek, lead author of the AAP breastfeeding guidance, says that infants “[continue] to benefit from the nutritional and immunologic contributions of breast milk into the second year of life,” but also says there isn’t much data on breastfeeding after 12 months.
“We don’t have great data beyond the first year of life, because we haven’t studied longer breastfeeding. We don’t even have data in the U.S. about how many families are breastfeeding beyond 12 months. Breastfeeding data in the U.S. is currently collected by the CDC [Centers for Disease Control and Prevention], but those data stop at 12 months,” Meek says. “Changing the recommendations to align with the evidence will help drive policy and data collection, as well as studies on outcomes.”
Meek also responds to criticism that these updated policy recommendations could be piling the stress on mothers who were already struggling to meet the six-month breastfeeding recommendation.
“There is no intent to put additional pressure on families,” Meek says. “The statement acknowledges that individual families, with the guidance of their pediatrician, will make decisions about infant feeding practices that best fit their child and their family. Paid maternity leave legislation to ensure workplace support for all women in all settings, acceptance of breastfeeding in public, and greater community support are all needed. The statement also aims to continue to establish breastfeeding as a cultural norm.”
The data on formula-feeding
Nicole Silber, a registered dietician, certified lactation consultant and creator of Tiny Tasters tells Yahoo Life that while formula lacks the immunological benefits of breast milk, it is safe and provides all the nutrients a baby needs — and parents shouldn’t be afraid to formula-feed if that’s what’s best for their family.
“Not only will the baby be healthy, the baby can go on to be cognitively just as advanced as their breastfed colleagues, and you can see them one day at Ivy League schools as well,” Silber says of formula-fed infants.
“As far as the food supply goes, baby formula is the most regulated product. So formula companies have to have very strict standards about the ingredients that can go in, about the composition,” she adds. “It really does mimic breast milk as far as the percentage breakdown of the macronutrients, as well as the micronutrients.”
Oster says that while formula-fed babies may have a slightly higher risk of some gastrointestinal illnesses, eczema or ear infections in their first year, the impacts of formula feeding instead of breastfeeding are small and only appear early in a child’s life.
And while they’re harder to quantify, she says the benefits of formula feeding on some parents’ overall well-being are worth noting as well.
“There are benefits to parents being happy and feeling confident, and like they are doing a good job and not being depressed. Now, is that necessarily delivered by formula? No. But I think it is true that for at least some people, the pressure to breastfeed, the anxiety around breastfeeding, the experience can really affect their mood [and] can really affect the way that their time with the baby goes. ... I think we are not measuring that enough,” Oster says.
"We can see the same pieces of data, and we make different choices."
Choosing how to feed your baby is one of the first parenting decisions a new mom or dad makes, so the stakes can feel extremely high. Oster and Silber say that may be a reason why breastfeeding vs. formula feeding is often such a fraught, emotional topic — and a point of contention on the internet.
“I think we all want our choices to be right," Oster says. "We want to have done the right thing. And we want to have done the right thing so much that we want it to be right for everybody.”
In her work as a pediatric nutritionist, Silber says she has observed that food is very personal for a lot of her clients, and disagreements over feeding — within families and online — often extend well beyond breast milk and formula. She points out that choices such as whether to introduce pureed foods or take a baby-led weaning approach with solid foods are also hot parenting topics rife with internet-shaming.
“Parents come in with their own set of ideas from how they were fed as children, or their own relationships with food, so it’s just a very emotional decision,” Silber says. “This is the first place in parenting where they can find their voice, and they have to learn to minimize the noise. I always say, ‘Trust your health care professionals who are trained in this, and not what you read on the internet.’”
One way to beat this culture of internet-shaming, Oster says, is for people to accept that parents can look at the same data and draw different conclusions.
“We can see the same pieces of evidence, we can see the same pieces of data, and we make different choices because we have different constraints and different desires and different preferences and different things that work for our family,” she says.
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