Katie Hinde: What we don't know about mother's milk
Breast milk grows babies' bodies, fuels neurodevelopment, provides essential immunofactors and safeguards against famine and disease -- why, then, does science know more about tomatoes than mother's milk? Katie Hinde shares insights into this complex, life-giving substance and discusses the major gaps scientific research still needs to fill so we can better understand it.
Have you ever heard the one about how breastfeeding is free?
Yeah, it's pretty funny, because it's only free if we don't value women's time and energy. Any mother can tell you how much time and energy it takes to liquify her body -- to literally dissolve herself --
as she feeds this precious little cannibal.
Milk is why mammals suck. At Arizona State University, in the Comparative Lactation Lab, I decode mothers' milk composition to understand its complexity and how it influences infant development. The most important thing that I've learned is that we do not do enough to support mothers and babies. And when we fail mothers and babies, we fail everyone who loves mothers and babies: the fathers, the partners, the grandparents, the aunties, the friends and kin that make our human social networks. It's time that we abandon simple solutions and simple slogans, and grapple with the nuance.
I was very fortunate to run smack-dab into that nuance very early, during my first interview with a journalist when she asked me, "How long should a mother breastfeed her baby?" And it was that word "should" that brought me up short, because I will never tell a woman what she should do with her body.
Babies survive and thrive because their mother's milk is food, medicine and signal. For young infants, mother's milk is a complete diet that provides all the building blocks for their bodies, that shapes their brain and fuels all of their activity. Mother's milk also feeds the microbes that are colonizing the infant's intestinal tract. Mothers aren't just eating for two, they're eating for two to the trillions. Milk provides immunofactors that help fight pathogens and mother's milk provides hormones that signal to the infant's body.
But in recent decades, we have come to take milk for granted. We stopped seeing something in plain sight. We began to think of milk as standardized, homogenized, pasteurized, packaged, powdered, flavored and formulated. We abandoned the milk of human kindness and turned our priorities elsewhere.
At the National Institutes of Health in Washington DC is the National Library of Medicine, which contains 25 million articles -- the brain trust of life science and biomedical research. We can use keywords to search that database, and when we do that, we discover nearly a million articles about pregnancy, but far fewer about breast milk and lactation. When we zoom in on the number of articles just investigating breast milk, we see that we know much more about coffee, wine and tomatoes.
We know over twice as much about erectile dysfunction.
I'm not saying we shouldn't know about those things -- I'm a scientist, I think we should know about everything. But that we know so much less --
about breast milk -- the first fluid a young mammal is adapted to consume -- should make us angry. Globally, nine out of 10 women will have at least one child in her lifetime. That means that nearly 130 million babies are born each year. These mothers and babies deserve our best science.
Recent research has shown that milk doesn't just grow the body, it fuels behavior and shapes neurodevelopment. In 2015, researchers discovered that the mixture of breast milk and baby saliva -- specifically, baby saliva -- causes a chemical reaction that produces hydrogen peroxide that can kill staph and salmonella. And from humans and other mammal species, we're starting to understand that the biological recipe of milk can be different when produced for sons or daughters. When we reach for donor milk in the neonatal intensive care unit, or formula on the store shelf, it's nearly one-size-fits-all. We aren't thinking about how sons and daughters may grow at different rates, or different ways, and that milk may be a part of that.
Mothers have gotten the message and the vast majority of mothers intend to breastfeed, but many do not reach their breastfeeding goals. That is not their failure; it's ours. Increasingly common medical conditions like obesity, endocrine disorders, C-section and preterm births all can disrupt the underlying biology of lactation. And many women do not have knowledgeable clinical support.
Twenty-five years ago, the World Health Organization and UNICEF established criteria for hospitals to be considered baby friendly -- that provide the optimal level of support for mother-infant bonding and infant feeding. Today, only one in five babies in the United States is born in a baby-friendly hospital. This is a problem, because mothers can grapple with many problems in the minutes, hours, days and weeks of lactation. They can have struggles with establishing latch, with pain, with milk letdown and perceptions of milk supply. These mothers deserve knowledgeable clinical staff that understand these processes.
Mothers will call me as they're grappling with these struggles, crying with wobbly voices. "It's not working. This is what I'm supposed to naturally be able to do. Why is it not working?" And just because something is evolutionarily ancient doesn't mean that it's easy or that we're instantly good at it. You know what else is evolutionarily ancient?
Sex. And nobody expects us to start out being good at it.
Clinicians best deliver quality equitable care when they have continuing education about how to best support lactation and breastfeeding. And in order to have that continuing education, we need to anchor it to cutting-edge research in both the life sciences and the social sciences, because we need to recognize that too often historical traumas and implicit biases sit in the space between a new mother and her clinician. The body is political. If our breastfeeding support is not intersectional, it's not good enough. And for moms who have to return for work, because countries like the United States do not provide paid parental leave, they can have to go back in as short as just a few days after giving birth.
How do we optimize mother and infant health just by messaging about breast milk to moms without providing the institutional support that facilitates that mother-infant bonding to support breastfeeding? The answer is: we can't. I'm talking to you, legislators, and the voters who elect them. I'm talking to you, job creators and collective bargaining units, and workers, and shareholders. We all have a stake in the public health of our community, and we all have a role to play in achieving it. Breast milk is a part of improving human health. In the NICU, when infants are born early or sick or injured, milk or bioactive constituents in milk can be critically important. Environments or ecologies, or communities where there's high risk of infectious disease, breast milk can be incredibly protective. Where there are emergencies like storms and earthquakes, when the electricity goes out, when safe water is not available, breast milk can keep babies fed and hydrated. And in the context of humanitarian crises, like Syrian mothers fleeing war zones, the smallest drops can buffer babies from the biggest global challenges.
But understanding breast milk is not just about messaging to mothers and policy makers. It's also about understanding what is important in breast milk so that we can deliver better formulas to moms who cannot or do not breastfeed for whatever reason. We can all do a better job of supporting the diversity of moms raising their babies in a diversity of ways.
As women around the world struggle to achieve political, social and economic equality, we must reimagine motherhood as not the central, core aspect of womanhood, but one of the many potential facets of what makes women awesome.