Breasts

Cover Page

About the Author

Title Page

Copyright

Dedication

Introduction
•
Planet Breast

1 • For Whom the Bells Toll

2 • Circular Beginnings

3 • Plumbing: A Primer

4 • Fill Her Up

5 • Toxic Assets: The Growing Breast

6 • Shampoo, Macaroni, and the Americal Girl: Spring Comes Early

7 • The Pregnancy Paradox

8 • What's For Dinner?

9 • Holy Crap: Herman, Hamlet, and the All-Important Human Gut

10 • Sour Milk

11 • An Unfamiliar Wilderness: Periods, the Pill, and HRT

12 • The Few, the Proud, the Afflicted: Can Marines Solve the Puzzle of Breast Cancer?

13 • Are You Dense? The Aging Breast

14 • The Future of Breasts

Acknowledgements

Notes

Permission Credits

Footnotes

Save the Tatas

— BUMPER STICKER

F
UNBAGS. BOOBSTERS. CHUMBAWUMBAS. DINGLE BOBBERS.
Dairy pillows. Jellybonkers. Num nums.
When I was growing up, my mother called them
ninnies.
That word, according to
Webster’s,
means “fools,” and lists
nitwits, nutcases,
and
boobs
as synonyms. For my own children, I amended the word to
nummies,
thinking it a bit kinder. Looking up its etymology recently, I found the word defined as “yummy,” but its origin may stem from
numbskull.
We love breasts, yet we can’t quite take them seriously. We name them affectionately, but with a hint of insult. Breasts embarrass us. They’re unpredictable. They’re goofy. They can turn both babies and grown men into lunkheads.

For such an enormously popular feature of the human race— even today, when they are bikinied, bared, flaunted, measured, inflated, sexted, YouTubed, suckled, pierced, tattooed, tassled, and
in every way fetishized—it’s remarkable how little we actually know about their basic biology. We know some things: they appear out of nowhere at puberty, they get bigger in pregnancy, they’re capable of producing prodigious amounts of milk, and sometimes they get sick. We know men even get them once in a while, and that tweaks us out.

Not even the experts among us are certain why all these things happen, or even why we have breasts in the first place. But the urgency to know and understand breasts has never been greater. Modern life has helped many of us live longer and more comfortably. It has also, however, taken a strange and confounding toll on our breasts. For one thing, they are bigger than ever, according to lingerie manufacturers and purveyors who are ever increasing their cup offerings to sizes like H and KK. We are sprouting them at younger and younger ages. We are filling them with saline and silicone and transplanted stem cells to change their shape. Most of us are not using them to nurture infants anymore, but when we do, our breast milk contains industrial additives never tasted by our ancestors and never meant to be digested by humans at all. More tumors form in the breast than in any other organ, making breast cancer the most common malignancy in women worldwide. Its incidence has almost doubled since the 1940s and is still rising. Breasts are living a life they’ve never lived before.

Fortunately, scientists are beginning to unveil the secrets of breasts, and with those secrets, a new way of looking at human health and our decidedly complicated place in nature. To understand the transformation, we need to go back in time, to the very beginning. We must first ask, Why breasts? Why us? We share 98 percent of our genes with chimps, but among that immeasurable 2 percent are the ones governing breasts. Chimps, unlucky sods, don’t have them. In fact, we are the only primates so endowed with soft
orbs from puberty onward. Other female primates develop small swellings while lactating, but they deflate after weaning. Breasts are a defining trait of humanity, and mammary glands define our entire taxonomic class. Carolus Linnaeus understood. That’s why he named us mammals.

Breasts are us.

I DIDN’T THINK A LOT ABOUT MY BREASTS UNTIL I BECAME A
mother. My breasts developed about the normal time. I liked them fine. They were small enough not to get in the way of sports or cause backaches, big enough that I knew they existed, symmetrical enough to look okay in a bathing suit on the rare occasions when I wore one while growing up in New York City. I wasn’t like Nora Ephron, who wrote an essay for
Esquire
about how she obsessed over her small breasts in the 1950s, the era of the torpedo bra, in California: “I would sit in the bathtub and look down at my breasts and know that any day now, any second now, they would start growing like everyone else’s. They didn’t.”

Poor Nora. Her worry acknowledged a truth that had been evolving since the sun set on the Pleistocene: breasts are really important. Consider this: in our mammalian ascent, being breastfed allowed us a youthful pass from gathering, chewing, digesting, and purifying food found in nature. Other animals such as reptiles had to live near specialized, high-fat food sources. Mammals just had to be near their moms, who do all that work for them. Mammals had more flexibility during times of climate change and food scarcity. After lactation evolved (from sweat glands) in the Mesozoic, mammals gained ascendancy over dinosaurs. The world became a different place.

Breasts have helped advance our own species’s evolution in ways
both self-evident and unexpected. With their rich stores of milk, they allowed our newborns to be born smaller and our brains to grow bigger. Having smaller babies meant our hips could be smaller, assisting our ascent into bipedalism. Breast-feeding may well have enabled the development of gesture, intimacy, communication, and socialization. Our nipples helped develop and prepare the human palate for speech and gave us a reason to have lips. So, in addition to greasing the way to our global domination, breasts begat the fine art of kissing. It was a tall order, but breasts were up to it.

Millions of years of evolution and environmental pressure created an organ that was pretty darn fabulous, or so we thought.

MINE LOOKED FABULOUS FOR ABOUT NINE MONTHS, WHILE I WAS
pregnant with my first child. After he was born, my breasts became wondrously utilitarian for the first time. But for a piece of finely tuned evolutionary machinery, mine often malfunctioned. They became objects of betrayal, frustration, self-doubt, and excruciating pain. Metaphors of aeronautics were now applied with disturbing frequency. I didn’t employ the correct “latch-on” or “suction disengagement,” and my nipples paid the price. A week after my son was born, I came down with my first case of mastitis, a practically medieval systemic infection that starts in a clogged milk duct. I would endure three more cases before the first year was out.

Although I grew to love breast-feeding, I am not a dewy-eyed sprite about it. Breasts are virtually the only organ the body has to learn how to use. The process isn’t for everyone. I was certainly swayed by visions of the purity and goodness of breast milk. While baby formula is derived from either cow’s milk or soy protein, human breast milk is perfectly suited to the human baby, as we are often told in the mommy literature. It contains
hundreds of substances—including ones that fight germs—many of which cannot or have not been synthesized in formula. Breast milk is always the right temperature; it has the correct balance of lipids, proteins, and sugars. It is medicinal, nutritious, and, to a baby, delicious. It was designed to be the perfect food, and I, new mother, was sold.

I was happily nursing my second child, blithely backstroking through that magic bubble known as the mother-infant pair-bond, when I stumbled upon a news report that would forever alter my perception of breasts. I read that scientists were finding industrial chemicals in the tissues of land and marine mammals as well as in human breast milk. So much for the blissful insularity of early motherhood. Along with their more exalted roles, breasts, I learned, are also the catchment for our environmental trespasses. I realized my breasts connected me not just to my children, but me (and by extension, my children) to my neighboring ecosystem. Breastfeeding, it turns out, is a very efficient way to transfer our society’s industrial flotsam to the next generation.

I released my breast from my daughter’s airlock and searched for answers. What toxic load had I already bequeathed my children by nursing them? What did it mean to their health, and to mine? Was it still okay to breast-feed? How did these chemicals interfere with our bodies? Could we ever make our milk pure again?

I did what journalists do and wrote about it. For a piece published in the
New York Times Magazine,
I sent my breast milk off to Germany to have it tested for flame-retardants, a common class of chemicals known to accumulate in fat and cause health problems in lab animals. My levels came back higher than I expected and ten to a hundred times higher than those found in European women. My exposure came from electronics, furnishings, and food. I also had my breast milk tested for other chemicals, including perchlorate, a
jet-fuel ingredient, which certainly is not what baby has in mind for dinner. My results kept coming back positive, with levels about “average” for Americans. It was a discouraging revelation of how thoroughly polluted we’ve become in the early twenty-first century.

“Well, at least your breasts won’t spontaneously ignite!” quipped my husband, trying to make the best of a situation over which we were virtually helpless. But I was reeling. The chemical cocktail in my chest collided with the journalist in my head. I wanted to find out how this elixir of evolution had come to meet such a diminished fate. Beyond that, I had to wonder how modern life was changing our breasts in other ways, and changing our health.

The answers weren’t always easily forthcoming.

PERHAPS NOT SURPRISINGLY, BREASTS HAVE OFTEN ELUDED
clearheaded thinking. Every set of eyes sees them a little bit differently. Rather than naming us all mammals, Linnaeus could have classified us by our shared ear-bone construction or four-chambered heart, but in singling out our unique mammae, he appears to have had a political motive as well as a scientific one. Linnaeus was the father of seven children. One of the conventions he abhorred was the practice of wet-nursing, in which the infants of the European middle and upper classes were literally farmed out to be breast-fed by surrogates. As a result, many babies died of malnutrition and disease. In 1752, a few years before Linnaeus introduced the term
Mammalia
into his tenth edition of
Systema Naturae,
he wrote a treatise on “Mercenary Wet-Nurses.” The science historian Londa Schiebinger argues that while Linnaeus cared about infant health, he was also deeply perturbed by the possibility of greater equality between the sexes during the Enlightenment. To Linnaeus, a
woman’s rightful place was in the home, acting as nature intended. To prove it, we would now be called mammals.

Then again, maybe Linnaeus just liked breasts. He was hardly the only man of science to conscript this body part into ideological service. The breast has always been a favorite of evolutionary biologists, who imbue it with colorful origin stories that may or may not be rooted in reality. Scientists have spent decades looking (and looking) at the breast, trying to figure out how on earth humans got so lucky. For years now, many have been seeing breasts as a wonderful adornment—like the peacock’s tail—designed to attract the opposite sex. When humorist Dave Barry wrote, “The primary biological function of breasts is to make males stupid,” he was summing up a half century of scholarship on the subject. Breasts, said a whole generation of academics, evolved because men loved them and preferred to mate with early cave women fortunate enough to have them.

By the latter quarter of the twentieth century, though, as women climbed the ranks of anthropology and biology departments, they had—and continue to have—some other ideas about how these mysteries arrived on the female chest. These gate-crashers hypothesized that it was actually the maternal woman who drove the evolution of breasts. Perhaps our she-ancestors needed those few extra grams of thoracic fat to gestate and nurture their babies, who are, after all, the pudgiest little primates in the history of the earth.

The debate over breast evolution is important, because the creation stories color how we see breasts, how we use them, and how we burden them with our expectations. Because the dominant story has been all about the visuals, it discounts what’s actually
in
breasts. How do they work? How are they connected to the rest of the body, and how are they affected by a larger ecology?

I WASN’T EXPECTING TO PONDER THESE QUESTIONS. BUT WRITING
that magazine article opened up a whole new world of environmental health. Our bodies, I learned, are not temples. They are more like trees. Our membranes are permeable; they transport both the good and the bad from the world around us. Twentieth-century medicine taught us that germs make us sick, but human health, I came to realize, is far more complex than this model. It is also governed by the very places we live and the small-print ingredients in the water we drink, by the molecules we touch and breathe and ingest every day. It became increasingly clear that we are not simply agents of environmental change; we are also objects of that change.

And breasts are a particularly vulnerable and visible pair of objects. To their credit and their detriment, breasts were built to be great communicators. From their earliest, circular beginnings, breasts have been highly sensitive to the world around them, conversing both within and outside the body. Because breasts store fat, they store toxic, fat-loving chemicals. Some of these substances persist for decades in our tissues. Breasts also contain a dense supply of receptors that sit on cell walls like hungry Venus flytraps, waiting around to catch passing molecules of estrogen, nature’s very first hormone. It’s an ancient habit. Before advanced organisms produced their own estrogen, cells had to get it from elsewhere. Our twenty-first-century breasts are still looking for it, and they’re getting a lot more than they bargained for. Plants make estrogenic compounds, and so do chemical and pharmaceutical corporations, often unintentionally. These chemicals—estrogen variants or mimics—interact with our cells in ways that are both subtle and overt. Our breasts soak up pollution like a pair of soft sponges.

To understand why our breasts so easily consort with molecules of bad repute, I needed to learn how cells work and how they respond to changes in the environment. During a year as a research fellow in environmental journalism and then as a visiting scholar at the University of Colorado, I studied cells, genetics, and endocrinology. My continued quest took me to corners both dark and well lit, to the experts working in the emerging fields of epigenetics and environmental endocrinology, as well as in the more established fields of evolutionary, cellular, and cancer biology.