Breasts (19 page)

This HAMLET ditches the pretty soliloquys and dons a superhero cape, diving into the nuclei of malignant (and viral) cells and freezing the gears. It effectively prevents malignant DNA from replicating and then in a final grand stage gesture causes the cells to implode. Weirdly and auspiciously, it seems to destroy only bad cells, leaving the good ones alone. Laboratory experiments have shown that HAMLET kills forty different types of cancer cells in a dish, including those of the bladder, lymphoma, skin, and brain, but it has not been tested much in humans yet. Still, the reason Svanborg began looking at milk is that several studies found that formula-fed children have significantly higher rates of childhood lymphoma than their breast-fed peers.

All this ought to make nursing mothers feel a little more valuable. Maybe they’ll wise up and start registering with insurance companies as health-care providers. Or maybe they’ll join the rawmilk underground. A few already have: an Internet site called Only The Breast lists classifieds with wording like “scrumptious mommy milk.” At four dollars per ounce, it costs 262 times the price of a barrel of oil. The marketplace for human milk in most of the United States and in the rest of the world is unregulated so far, despite the fact that it’s capable of transmitting hepatitis and other maternal diseases along with lactoferrin. Nonprofit human milk banks (there are eleven in North America) heat the milk to pasteurize it, but the process also kills some of its bioactive ingredients. While donor milk is used mostly in neonatal intensive care units for preemies, older children and adults sometimes buy it for treating various illnesses or for soothing the harsh mucosal effects of chemotherapy.

As Bruce German had reminded me in Peru, these breakthroughs in the understanding of milk are not just interesting; they are fundamentally altering what we know about human health. “The
story that is compelling to me is the fascinating interplay between bacteria and humans,” he’d said. “This whole story is part of a revolution in science itself, where the chemistry-dominated science of the twentieth century is giving way to the biology-dominated science of the twenty-first century. Such a shift is sometimes difficult to appreciate, especially for people outside the scientific community. For milk and bacteria there is an easy point of entry for people to see the vivid contrast: twentieth-century chemistry—use chemicals to kill all bacteria; twenty-first century—use biomolecules and organisms to guide a supportive microbial ecology. It’s a new world of science.”

NATURE HAS DESIGNED MILK TO BE INGENIOUS, BUT IT’S THE
breast itself that directs the show. Biologists bat around the concept of “crosstalk,” how one part of the body communicates with another and vice versa. In the case of the lactating breast, the organ is communicating not only with its immediate landlady but also with the infant. From the very beginning, the breast appears to know whether the infant is a boy or a girl, at least in rhesus macaque monkeys, which have similar milk to humans and have been studied more comprehensively than their human relatives. In the macaques, mothers of sons produced fatter, more-energy-dense milk. Katherine Hinde, a professor in the human evolutionary biology department at Harvard University, thinks this might be because macaque males have slightly higher growth rates and as adults weigh about 30 percent more than females (human males weigh about 15 percent more than females). But Hinde has another, more devious social theory as well. She discovered that macaque mothers produce fattier milk for sons, but they make
more
milk for daughters, meaning the maternal
energy investment is about the same. In that matrilineal primate society, daughters learn from hanging around their mothers longer and more often, and thinner milk means they stay close for more frequent feedings. The sons, by contrast, might be “tricked” by the mother’s fattier milk into feeling sated and therefore not feeding as often. It’s not a bad thing for the sons; they have more time to play and explore, skills they’ll need down the road when they leave the group.

How does the breast know whether the infant is male or female? Probably because hormones called placental lactogens talk to the breast during pregnancy, when it is building the structures it will need for making milk. Girls evidently get the skim-milk machinery. Mom wants to produce good milk, but she doesn’t want to kill herself doing it, which brings up an interesting dynamic between mother and infant: competition. Babies have evolved their own tricks to get as much of their mother’s resources as they can: Witness the tightly interwoven placenta (made by the embryo) that becomes essentially parasitic. The mother’s body has genes to expel the fetus a little before the due date. The baby’s genes—put there by the father, presumably—tell it to stay put a little longer.

The breast picks up the tug-of-war after birth, slipping endocannabinoids into the milk. Note the root
cannabis
in there. These substances, which cause the munchies, probably play a role in enticing infants to eat. But they also regulate appetite so infants feel
very full
by the end of a feed and thus don’t eat too much. Interestingly, formula lacks these compounds, and formula-fed babies have a notoriously higher caloric intake. It’s one of the speculations about why we have a childhood obesity epidemic.

While looking out for the mother, the breast is also looking out for the baby. It is constantly sussing out his or her nutritional and
immunological needs. When the breast senses an infection brewing in the baby, it somehow tips off the mother’s immune system and in turn the milk puts out more lactoferrin and the relevant antibodies. When the baby is older than one year, the milk contains more fat and cholesterol to match the baby’s energy needs. When a baby is born prematurely, the mother’s milk, as if anticipating its role, contains more protein and caloric density for a tiny tummy. Is it a coincidence or did we evolve that way, despite the unlikelihood that many preemies survived in our early history?

The breast is like a smartphone and juice bar in one. It communicates with the mother’s body, the baby’s body, and the environment. The breast knows the condition of the mother. Stress, for example, can cause her to hold back her output of milk. It can also send more cortisol into the milk, which appears to affect the longterm personality of sons (but not necessarily daughters), perhaps making them more exploratory or hypervigilant to grow up in a difficult environment. We know that a tough environment can affect a mother’s stress levels. After the terrorist attacks of 9/11, many new mothers all over the country experienced temporary problems producing enough breast milk. My son was eight weeks old. Looking back, I wonder if this event played a role in our early difficulties with supply and demand. Unlike my mother, though, I never kept a nursing log.

Cells in the breast communicate with cells in the bone, telling the bone how much calcium to release for milk production and when to start guarding it again. A mother loses up to 6 percent of her calcium for her baby, but the stock more than fully replenishes within a few months after weaning. In terms of things like energy and minerals, breast-feeding takes a severe toll on mothers, though not as severe as the toll of gestating and delivering a fetus.
Breast-feeding actually helps the mother recover from these events by tweaking her metabolism and protecting her heart. It’s a critical part of how the enterprise was designed for our benefit as well as our baby’s.

Internist and researcher Eleanor Schwarz had told a story in Peru about her inspiration for a study. “I was storing some of my milk in bottles in the refrigerator, and I noticed it looked like buttermilk,” she’d recalled. “That’s how fatty it is. Was there some relationship between the bottle of butter I was storing in the fridge and my future cardiovascular risk?” In other words, was the fact that her body was mobilizing her fat and siphoning it into milk helpful to her arteries or not? Some studies had shown that women who breast-feed lose more pregnancy weight than mothers who don’t, but the data were inconsistent, and there wasn’t much information about types of fat they lose or where it came from in their bodies.

Schwarz started crunching the numbers from the giant data set of the Women’s Health Initiative, a long-term national health study. She found that while there wasn’t much difference in weight loss between mothers who did and didn’t breast-feed, women who didn’t were 10 percent more likely to suffer cardiovascular disease and type 2 diabetes later on. She examined numbers from another study of 100,000 slightly younger women and found that those who breast-fed for just three months had a threefold lower risk of aortic or arterial calcification after adjusting for other lifestyle and economic factors. While pregnancy itself had put these women at risk for weight gain compared to women with no children, lactation had returned their lipid profiles back to baseline, a benefit that remained for decades. Mothers who nursed their babies also had less belly fat, which is known to be linked to heart and metabolic problems. “My current thinking,” Schwarz concluded, “is that humans are mam
mals, and never lactating is not normal. I think breast-feeding plays an important role in a woman’s recovery from pregnancy. It’s like liposuction in terms of how much fat it’s pulling off the body.”

A NURSING MOTHER, OF COURSE, HAS NO IDEA ALL THIS CROSS
talk is going on. She just knows her baby is hungry, and she can help. But food is a powerful currency. Add some hormones and she’s a goner. Within hours of birth, my son and I (and then my daughter and I) became what scientists call “the mother-infant dyad”—a fully self-contained unit. For us, the hinge of it was a pair of breasts. Knowing that I could give my babies all they needed was nothing short of astonishing. Through breast-feeding, I grew more confident in my ability to be a mother.

Unfortunately, not many mothers get this far. For such a clever, highly evolved system, it’s too bad that breast-feeding is so ridiculously hard to do. I recently chatted with a young mother at a family gathering. Her eight-week-old baby girl was swaddled in pink, happily sleeping in her arms. “I tried breast-feeding for five days,” said the woman, “but then the pain started. I was like, “that’s it, I’m done.” She’s not alone; approximately 80 percent of newly lactating mothers have sore nipples, and many of them quit at the first sign of discomfort.

The big contradiction is that breast-feeding is so natural, and yet so completely unintuitive. What’s really natural is for women to have a love-hate relationship with it, and this is something the lechistas don’t tend to admit. Just as we’ve evolved to breast-feed, we’ve also evolved to be flexible, even whimsical, in our feeding habits. Some cultures and individuals nurse their children for years; others, not at all. In fact, humans are the only primates who wean
their young long before they can forage on their own. We do this because we can, not because it’s always the best thing for the baby.

Anthropologist Dan Sellen from the University of Toronto, who was also in Peru, said that most humans in foraging cultures weaned their young at about thirty months, “a pattern known to be optimal for growth and development.” But there were always outliers—societies where the norm was nursing much further out or for much shorter periods. This flexibility—born from our human opportunism—may be natural, but it may also be problematic at the extremes enabled by manufactured formula, according to Sellen. As he pointed out, early weaning is sometimes okay from a nutritional perspective, but less so from an immunological one, especially as you look globally. When I returned from Peru, he sent me a recent paper of his. Its conclusion: the “mismatch between optimal and actual infant feeding practices in contemporary populations is widespread and presents a major public health challenge.”

In a book about the unnatural (as well as the natural) history of the breasts, here is where we must deliver some more sobering as well as some strange news: not only is breast-feeding hardly practiced these days the ways nature intended, but the very stuff itself is oddly compromised.

In a great paradox of modern life, just as we’re on the brink of truly understanding what’s in human milk that can help us, the components are shifting.

As of late, breast milk has an unanticipated, new, ingredients label.

To recognize milk which is bad: thou shalt perceive that its smell is like
snj
of fish. To recognize milk which is good: its smell is like powder of manna.

—
EBERS PAPYRUS
,
ca. 1550 BC

I
F HUMAN BREAST MILK, NATURE’S PERFECT FOOD, CAME
stamped with an ingredients label, it would read something like this: 4 percent fat, vitamins A, C, E, and K, sugars, essential minerals, proteins, enzymes, and antibodies. It contains 100 percent of the recommended daily allowance of virtually everything a baby needs to grow, plus, as we’ve seen, a solid hedge of extras to help ward off a lifetime of diseases ranging from diabetes to cancer. Despite exhaustion, visiting relatives, and dirty laundry, every time we nurse our babies, the love hormone oxytocin courses out of our pituitaries like a warm bath. Human milk is like ice cream, penicillin, and the drug ecstasy all wrapped up in two pretty packages.

But read down the label a little farther, and the fine print sounds considerably less appetizing: DDT, PCBs, trichloroethylene, perchlorate, dibenzofurans, mercury, lead, benzene, arsenic. When we
nurse our babies, we feed them not only the fats and sugars that fire their immune systems, cellular metabolisms, and cerebral synapses. We also feed them, in albeit miniscule amounts, paint thinners, dry-cleaning fluids, wood preservatives, toilet deodorizers, cosmetic additives, gasoline by-products, rocket fuel, termite poisons, fungicides, and flame-retardants.

If, as Cicero said, your face tells the story of your mind, your breast milk tells the decades-old story of your diet, your neighborhood, and increasingly, your household décor. Remember that old college futon? It’s there. That cool paint in your bathroom? There. The chemical cloud your landlord used to kill cockroaches? Yup. Ditto, the mercury in last week’s sushi, the benzene from your gas station, the perfluorooctanoic acid (an anti-grease coating) from your latte cup and sofa upholstery, the preservative parabens from your face cream, the chromium from your nearby smoke stack. One of the ironic properties of breast milk is that its high fat and protein contents attract heavy metals and other contaminants. If human milk were sold at the local Piggly Wiggly, it would exceed the federal safety levels for some of those chemicals in food.

On a body weight basis, the dietary doses our babies get are much higher than the doses we get. This is not only because they’re smaller, but also because their food—our milk—contains more concentrated contaminants than our food. It’s the law of the food chain, and it’s called biomagnification.

To refresh that lesson from seventh grade, here’s how it works: Animals at the top of the food chain receive the concentrated energy and persistent chemicals of all of the biota underneath them. Each member up the food chain takes in approximately 10 to 100 times the load of fat-loving toxins of its counterpart below. This is why a
slab of shark meat contains more mercury than its weight in plankton. Ocean food chains are longer than terrestrial ones, so people who eat many marine carnivores carry higher body concentrations of some chemicals than the vegan who lurks at your local salad bar or even the steak lover next door. The Inuit, although they live in the remote Arctic with little nearby industry, are the most contaminated population on earth, besides victims of industrial accidents. But don’t picture Eskimo Man in sealskin on the top of the food chain. Picture his suckling baby, who occupies yet another trophic level higher up.

If that’s not creepy enough, some of the chemicals we pass on to our daughters will stay in their bodies long enough for them to bequeath them to their offspring. Even if we cleaned up our planet tomorrow, the industrial detritus of the last century has created a three-generation problem.

WHEN I WAS NURSING ANNABEL, I’D HEARD ABOUT THIS SORRY
state of affairs. I wanted to tell the story through what I learned from my own breast milk. There was a lot of emerging research about flame-retardants, in particular, because they were both so prevalent and believed to be disrupting hormonal systems in lab animals. At the time, only about a hundred other American women had had their milk tested for these substances as part of research studies, so I called Arnold Schecter at the University of Texas School of Public Health in Dallas. A medical doctor and professor, he’d been working for years on Agent Orange exposure and was now the go-to guy on flame-retardants. I would be Number 101.

I knew some of these chemicals would turn up in my breast
milk; they are found in virtually every animal and human tested around the globe. The levels in American women are considerably higher than in anyone else, and they may be high enough to affect our health and that of our children. These levels tell us that our world is full of unhappy and improbable surprises, like the fact that our computer casings are somehow ending up inside of our breasts. Our collective levels tell us we cannot hide from toxins, no matter how carefully we shop, eat, and vacuum.

I felt pretty confident my levels would be relatively low. There was no basis for this assumption other than that I tend to live a healthy lifestyle. I don’t smoke; I exercise. Since I had been pregnant or nursing two children for almost four years, I had been buying mostly organic food. Several years earlier we’d installed a threestage reverse osmosis filter on our tap water and ice-maker. At the time, I lived in a leafy, scenic town in Montana. It was far from brown clouds and belching diesel freeways, although we did live near two Superfund sites, which are more prevalent in Montana than national parks are.

There was one obvious strike against me, which is that I was an older mother and therefore had stored up more long-lasting toxins in my body than a younger mother. In my favor was that I was nursing my second child, which means somewhere around half of my lifelong store of chemicals had already been siphoned through breast-feeding into my firstborn, then three years old. Nursing a baby, ironically, is the ultimate detox diet. As for my son, unless he learns how to lactate someday, he’ll be stuck with my cast-off chemicals for a good long while.

Arnold Schecter had me ship my frozen vials of breast milk to Germany, where lab workers were capable of divining low levels
of contaminants through sensitive mass spectrometer chromatographs. Schecter would interpret the results in Texas. Waiting for results over the ensuing two months, I learned more about the pervasiveness of flame-retardants in everyday American life. I started to get a little more anxious. It was a creeping discomfort, akin to when a person next to you on an airplane hacks up a nasty cough, over and over. I eyed my son’s adorable foam airplane chair and the small tear in the car upholstery. I watched my son. Was he meeting his development targets? How was his attention span? I recognized that in its incremental way, alarm over toxic contamination creates a perfect storm for the overanxious parent of millennials. Now in addition to worrying about getting them into the right schools, dirty bombs, and car-seat recalls, we get to wonder whether our loveseats are emitting developmental neurotoxins.

One thing became clear: we live in a flame-retardant nation.

To understand how the substances ended up in everyone’s breast milk, one must go back to 1938, when a German chemist named Otto Bayer invented polyurethane to replace rubber from markets cut off by war. First a rigid polymer, it was used to coat warplanes and to line the soles of Nazi boots. By 1954, chemists could fill the carbon-based material with air bubbles, creating flexible foam. It was practically an industrial miracle: cheap, soft, and malleable. It transformed everything from refrigeration insulation to upholstered furniture to car bumpers and tires. As one industry website proclaimed, “Today, polyurethanes can be found in virtually everything we touch—our desks, chairs, cars, clothes, footwear, appliances, beds, the insulation in our walls, roof and moldings on our homes.”

There’s just one problem: it’s highly flammable, earning nick
names like liquid gas and fatal foam. A typical home filled with polyurethane products can literally burst into flames in five minutes once the petrochemical gasses heat up enough. Much household and office foam is treated with flame-retardants designed to delay ignition. The substances, which include bromine, chlorine, and phosphorous versions, came into widespread use after 1975— when California, under pressure from the bromine industry, passed a consumer safety standard for furniture flammability. Specifically, it required furniture to resist ignition for twelve seconds in tests with open flames and smoldering cigarettes.

It’s questionable whether or not these substances actually save lives. Nationwide, deaths from house fires are down on the order of 50 percent since the 1970s, a fact mostly attributed to fewer smokers and more smoke alarms. In fact, fire deaths have declined at a lower rate in California, the state with the most flame-retardant furniture (and the world’s highest recorded levels of these toxins in human tissue). Flame-retardants may buy you a few extra seconds before ignition, but the chemicals make the smoke, soot, and fire worse by releasing other by-products like dioxin, a known human carcinogen. Most deaths in fires are caused by inhaling smoke or toxic gases.

In order to reduce flammability, foams, plastics, and fabrics are soaked or coated in these mixtures, which have commercial names like Firemaster 550 and V6. In some furniture-foam pieces, these mixtures account for up to 30 percent of their weight. (A common misperception, though, is that mattresses contain these chemicals. They don’t, in case that helps you sleep better.) Most of the health research has been focused on a group of flame-retardants called PBDEs, polybrominated diphenyl ethers. A class of organic compounds, PBDEs have as one of their signature properties lipo
philia, or fat attraction—hence, their unwelcome appearance in our breast milk.

BREASTS, IT TURNS OUT, ARE A PARTICULARLY FINE MIRROR OF
our industrial lives. They accumulate more toxins than other organs and process them differently. We first clued into this in 1949, when a Westport, Connecticut, doctor named Morton Biskind examined a pregnant woman who had strange neuropsychiatric symptoms, including vomiting, muscle weakness, and “unbearable emotional turbulence.” He had been following scores of patients with acute poisoning from exposure to the ubiquitous pesticide DDT, which had hit the U.S. market a few years earlier. He’d heard the substance was being found in the milk of cows, rats, and dogs, so after the woman gave birth, he thought to test her breast milk. It was rich in DDT. Two years later, the scientist E. P. Laug published a study finding DDT in the milk of African-American mothers in Washington, D.C. In 1966, a Swedish researcher tested his wife’s breast milk for PCBs—polychlorinated biphenyls, used to insulate electrical transformers—after he discovered them in dead eagle tissue. Two years later, Sweden banned them, with the United States following in 1978.

Because of the widespread use and persistence of PCBs, they are still among the highest-concentration toxins found in breast milk, even from mothers born well after the ban. One of the few chemicals to be banned outright in the United States, PCBs have been well studied. In humans, at elevated levels they can interfere with thyroid functioning and contribute to such gender-bending problems as masculinized female infants and feminized male infants. Studies also show a relationship between exposure to PCBs and
breast, liver, and gall bladder cancer and lymphoma. Researchers in the Great Lakes region, the Arctic, and the Netherlands found that babies born to mothers with mid- to upper-range levels of PCB contamination (all due to eating diets rich in fish) have delayed learning capabilities, lower IQs, and reduced immunity against infections. Some problems have persisted into early adolescence, so far.

Molecularly, the flame-retardant PBDEs are eerily similar to their older cousins. But we may never have noticed flame-retardants showing up in living cells if not for a mysterious bout of animal poisoning in Michigan in 1974. That year, farm animals began suddenly losing weight, aborting calves, not lactating properly, salivating excessively, and suffering from diarrhea. A sluggish investigation followed, during which an enterprising government chemist finally discovered that workers at a plant that processed both animal feed and flame-retardants had inadvertently mislabeled the bags going to market. It was a classic Wile E. Coyote mix-up. Some foam got treated with food filler, and millions of animals statewide ate a bunch of flame-retardant—in this case, a compound called PBB. Eventually, ten thousand cows, two thousand pigs, four hundred sheep, and two million chickens had to be slaughtered, but not before nine million people ate contaminated dairy and meat over the course of a year.

In the years that followed, some adults who ate these products reported immune and thyroid diseases, acne, miscarriages, and other problems. A number of babies were also exposed to the substance in utero or through breast milk, and several EPA-funded studies have tracked their health outcomes. The girls who were exposed to the highest levels of PBB through breast milk reached puberty nearly a year earlier than those exposed only in utero or whose mothers nursed them with less contaminated milk. Exposed boys had higher
rates of urogenital birth defects and slower development. The girls, now women, are showing higher rates of miscarriage.

The Michigan event did not make huge news nationally, but toxicologists took note. When the Michigan-made flame-retardants were quietly taken off the market, PBDEs stepped in as replacements. Today we know the new compounds were not much safer. Swedish researchers first found them in river pike in 1981. Unlike PCBs and DDT, whose levels were gradually declining worldwide, PBDE levels were steeply rising. The Swedes decided to look for the chemicals in stored human milk samples, and what they found rocked the scientific community: from the early 1970s, when they first appeared commercially, to 1998, PBDE levels in breast milk were doubling every five years.

“No one had ever heard of them. We thought it was just a European problem,” said Kim Hooper, a toxicologist now retired from the California Department of Toxic Substances Control. “So we looked in San Francisco Bay seal blubber, and found a 100-fold increase over ten years.” Then the Americans, too, decided to look in human milk. When European scientists first saw the test results of American women, they thought there must be a mistake. Our levels were ten to forty times higher—a full order of magnitude— than those in women in Europe. The numbers were also doubling every five years, a rate unmatched by any known chemical since the 1960s. In the past two decades, our levels have risen so sharply that the curve resembles a rocket launch.