Our Own Devices: How Technology Remakes Humanity (8 page)

Confidence in science and aggressive marketing by manufacturers were not the only reasons
for the success of infant formula. Beginning in the 1920s, the breast was sexualized in a way that made public feeding potentially more sensitive than it had formerly been. Bottle-feeding was associated with scientific motherhood and at the same time with freedom from domesticity. Some bourgeois European circles also welcomed bottle-feeding as a step against prolonged oral gratification and for
the development of good habits. The result was a steady increase, though with many national and regional variations, in the proportion of bottle-fed infants between World War I and the 1960s. In one American study of 1958, 63 percent of infants returning home from the hospital were already consuming only formula, and 21 percent were fed only breast milk. Few employers
accommodated working mothers
who had nursing infants, but even in the Sweden of the 1960s, where new mothers remaining at home with their infants received 90 percent of their professional salaries, bottle-feeding prevailed. A revival of breast-feeding among middle- and upper-class women in North America and Europe began in the 1970s and remains a strong force, but it has delayed bottle-feeding rather than replaced it as a
routine of upbringing.
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In Europe and North America, the health effects of infant formula are still debated. In the great age of expansion of bottle-feeding from 1890 to 1950, infant mortality also dropped markedly—from 140 to fewer than 40 deaths per 1,000 live births in New York City, for example. Reduction of digestive and respiratory ailments, notably diarrhea and pneumonia, was especially
pronounced. In Sweden, an even more pronounced decline in mortality had begun in the late eighteenth century and continued through the nineteenth and early twentieth. In neither the United States nor Sweden did the trend appear to be affected by the spread of bottle-feeding or by the Depression of the 1930s. All this suggests that in affluent countries, formula-feeding was indeed a good alternative
to the wet nursing that had been practiced so widely in early modern Europe.
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The great unintended consequence of artificial feeding has arisen not in the industrial countries but in the developing world. Especially since the late nineteenth century, North American and European farmers have produced abundant milk. Breeding and animal nutrition alone have raised the annual yield of a dairy cow
from about 1,500 liters in the early nineteenth century to 6,500 liters—and for some breeds as much as 10,000 liters—today. Pasteurization has been commercialized since the 1890s, refrigerated trains have drastically reduced spoilage on the way to market or processing, and global beef imports have allowed more European farmers to specialize in dairying.

Meanwhile, the growth of cities and market
economies in Asia and Africa made processed infant formula a valuable export. In these markets, infant formula remains costly for all but a small segment of families. The formula producers applied with great success the scientific appeals that had been effective in the West. Infant formula was also promoted as a sign of modernity and education; elites adopted it as a mark of their political and
economic authority. In the rest of the population it was most influential in cities, where rapid migration and women’s industrial labor helped disrupt the transmission of breast-feeding techniques. Urban slum life and disease can also interfere with lactation. And even low-income women came to
share the privileged classes’ view of infant formula as a progressive and scientific alternative to breast-feeding,
and the Westernized taboo on the public display of breasts. Advertising linked formula with infant health as well as with prosperity and modernity. Intentionally or not, it persuaded many mothers who could have established lactation successfully that they suffered from “insufficient milk” syndrome. In some countries, “milk nurses” receiving sales commissions, some of them with real
nursing credentials and all easily confused with hospital staff, promoted manufacturers’ products to new mothers in hospitals. Inadvertently, distribution of millions of pounds of powdered milk for starving babies by the United Nations Children’s Fund (UNICEF) and other agencies in the 1960s helped legitimize substitute food in new markets. What helped the sick would surely benefit the well.
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The result instead was malnutrition and death. The first prominent crusader against formula-feeding in the Third World, the pediatrician Dr. Cicely Williams, had promoted condensed milk in combating kwashiorkor, a severe protein-calorie deficiency disease, in Africa. But in 1939, Dr. Williams, then working in Singapore, was disturbed by the consequences of feeding infants sweetened condensed milk.
In those days the product was not supplemented with vitamins D and A, so it had contributed to many cases of rickets and blindness. Speaking on “Milk and Murder” to the Singapore Rotary Club, Williams accused the producers of callous neglect of infant life in the interest of profit.

Well-meaning agencies as well as commercial interests could work against breast-feeding. Two leading pediatric
public health specialists, Derrick and Patrice Jelliffe, call the distribution of powdered milk by feeding programs in the 1940s and 1950s a “nutritional tragedy.” In the absence of health education programs, the product encouraged a shift to bottle-feeding. The commercial distribution of formula, far from reducing the rate of nutritional deficiences, increased them seriously. Bottle-fed babies gain
weight more slowly than breast-fed ones, and are more likely to suffer from bacterial and viral infections and parasites in their second year. Marasmus—a form of severe growth failure closely connected with the lack of high-calorie foods—is linked with bottle-feeding. Dilution of cow’s milk formulas to reduce costs is a special risk factor for marasmus in many poorer countries. Since mother’s milk
may be the only safe liquid in many regions and feeding bottles may be impossible to keep clean without refrigeration or sanitary storage areas, formula-feeding also promotes infections, especially diarrheal diseases that inhibit appetite and lead to
malnutrition and more illness. Meanwhile, the bottle-fed infant receives none of the protective substances in mother’s milk. In seven villages in
the Punjab studied in the 1950s, mortality among infants bottle-fed from birth was fully 95 percent during the first eleven months, compared with 12 percent among infants breast-fed from birth.
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United Nations—sponsored efforts to encourage industry regulation faltered. In the 1970s, social activists armed with the damaging statistics and with Derrick Jelliffe’s identification of “commerciogenic
malnutrition” in Jamaica began to urge restrictions on the marketing of infant formula in the developing world. A boycott of Nestlé, begun by religious groups and others, was resolved with a vote of the World Health Organization’s (WHo’s) World Health Assembly in 1981 establishing a UNICEF code restricting advertising and the distribution of samples and intended to put proprietary formulas under
strict medical supervision. Manufacturers’ literature now extolled the virtues of mother’s milk while encouraging an early transition to bottle-feeding. But activists, believing formula manufacturers were trying to circumvent the UNICEF code despite several amendments designed to close loopholes, renewed the boycott in 1988.
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In the First World, infant formula raises different
but equally interesting issues. Like the WHO, the American Academy of Pediatrics (AAP) strongly supports breast-feeding. In a 1997 policy statement it declared that “breastfeeding ensures the best possible health as well as the best developmental and psychosocial outcomes for the infant.” But the cohort born at the peak of formula-feeding, from 1946 to 1952, comprises the babies who started
the boom, and they flourished, as the science writer Natalie Angier and others have reminded breast-feeding advocates. Yet whatever their present health—could they not be even healthier?—they did not necessarily have an easy time as babies. Breast milk is an elaborate package of chemicals developed over millions of years of primate evolution to promote the newborn’s development and build up its
defenses against infection. Some of its constituent molecules keep microbes from spreading from the digestive tract into the body’s tissues; others reduce the availability of vitamins and minerals (especially iron) that disease-causing bacteria need; and still others help the work of immune cells and kill bacteria directly by attacking their cell walls. And a variety of white blood cells helps the
infant produce antibodies and attack microbes directly. A pediatrician
recalls how easily incorrect preparation of bottles by hospital formula rooms could caramelize the sugar and precipitate diarrhea. In fact, many infections are more common in bottle-fed infants deprived of the protective antibodies unique to mother’s milk. Even now, pediatric researchers estimate that 250 to 300 infants die
each year from diarrheal infections as a result of bottle-feeding; another 500 to 600 die from respiratory diseases. Middle ear infections, more frequent among formula-fed children, have been treatable with antibiotics, but the high price of therapy has included the rise of resistant strains of bacteria.
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Even more important and less well known is how formula-feeding affects the long-term welfare
of both infants and mothers. Whether to breast-feed or bottle-feed has always been a cultural as well as a biological decision. Mothers who choose one or the other method may well feed their children differently after weaning, give them more or less encouragement in school. They may be more or less affluent than other parents, and their children may have different peers and experiences. Bottle-fed
infants are also more likely to be given pacifiers, which in turn differ in design and in their effects on the development of the mouth.

Despite all these possible biases there is evidence—sometimes limited and controversial—of long-term benefits of breast-feeding. Breast-fed children may develop slightly higher intelligence than bottle-fed contemporaries. A number of chemicals that appear in
human milk but not in formula, including arachidonic acid (AA) and docosahexaenoic acid (DHA), are known to promote brain growth. Longer-term breast-feeding has been linked in one study to faster motor and cognitive development. In another, premature infants tube-fed with human milk had an 8.3-point IQ advantage over their formula-fed counterparts at the age of seven and a half—this after downward
adjustment to reflect their mothers’ educational and social status. Some studies show only weak or insigificant gains after adjustment for family background, but the very first study of feeding method and mental development, published in 1929, showed advantages for breast-feeding at a time when formula-feeding was chic and breastfeeding associated with immigrants and the working class.
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The
immune system also may be affected by infant feeding. The nutrition researcher Alan Lucas has pointed out that studies of other animals show effects of prenatal and postnatal nutrition on indicators of health from size and metabolism to obesity, hardening of the arteries, and longevity. There is evidence, if not yet proof, that there are critical periods in human development, “programming windows”
for stimuli that enable
or inhibit later behavior. Very early in their lives, chicks, mallard ducklings, and some infant mammals become attached to the first thing they encounter, in nature nearly always a parent but in the laboratory sometimes a human being, another animal, or even an object. Since the 1960s, scientists have been able to produce lifelong changes with brief early interventions;
rats receiving less nourishment in their first three weeks remain smaller than others. Baboons overfed in infancy gain weight in early adulthood as though by a delayed causal mechanism. Lucas believes nutritional programming may have effects on human health.
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Are we not only what we eat, but what we ate? Fragmentary but intriguing evidence exists. Inflammatory bowel diseases may be linked to
very early nutrition. Studies have shown that ulcerative colitis and Crohn’s disease (a chronic inflammatory disease of the intestines) are less common among those raised on breast milk. Another study suggests that artificial feeding has been responsible for the long-term increase in juvenile diabetes; the authors attribute a quarter of all cases to bottle-feeding. Because childhood infections of
the ear and the lower respiratory tract may lead to chronic respiratory illness, the early benefits of breast-feeding can carry through to later life. There are also indications that breast milk may reduce the risk of malignant lymphomas, multiple sclerosis, and coronary artery disease. Exclusive breast-feeding for at least four months after birth has been shown to reduce the risk of childhood asthma
significantly. The number of studies in each case is small, and breast-feeding advocates in medicine also acknowledge that human milk is no panacea; it probably only delays the onset of allergies, for example. But the studies have still contributed to medical organizations’ overwhelming support for extended breast-feeding.
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Industrial and postindustrial culture also affects the timing of feeding.
For most of human history, there was no supplementary feeding, and infants were allowed access to milk frequently, with short intervals between feeds. Most of today’s breast-feeding mothers, especially in economically advanced nations, nourish their infants fewer times each day. The original style is healthier for babies, helps prevent jaundice, and it’s less likely that overenthusiastic sucking
by hungry infants will cause the mother pain. While the standard U.S. breast-feeding handbook now recommends nursing “at least every two or three hours,” this is not feasible for many employed mothers, though their stored milk may be fed to their infants by sitters.
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Breast-feeding may also protect mothers in ways that are not fully
understood because our culture—even among most breast-feeding
mothers—departs from many of the patterns present during the evolution of our species. Katherine Dettwyler has argued persuasively that human infants follow a “hominid blueprint” for extended nursing. Studies of other living primate species have established a formula linking weight at maturity to age of weaning. For human weight, the formula predicts, conservatively, a natural age of weaning of
from 2.8 to 3.7 years, varying with adult female weight. Studies of gestation time and weaning suggest that in humans, as in chimpanzees and gorillas, breast-feeding would last at least six times as long as gestation rather than for nine months, as many medical texts assert. Other primate studies link weaning strongly with the eruption of the first permanent molar; this happens to human children,
regardless of nutritional status, at the age of 5.5 to 6 years, about the time they acquire adult immune competence. Thus infants are biologically inclined to continue nursing until their third or fourth year or even longer. Katherine Dettwyler believes there may be benefits for both mothers and infants in prolonged lactation; she cites research that suggests that small but significant numbers of
mothers in industrial societies continue suckling their children discreetly well beyond the second and third year. Indeed, in 1999 a Chicago newspaper found a local four-year-old preschooler with his own computer who scandalized guests at a parental party by taking such a milk break, raising his fists “Muhammad Ali—style, and declar[ing], ‘That was sooooo good.’” And despite the reservations of some
psychologists, there seem to be no physical or mental ill effects among late-nursing children. One of them in Chicago grew up to be a massive offensive linesman at Texas A&M who says he has not been sick since eighth grade and has no memories of nursing.
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