1. Breast-feeding is natural.

It depends on how you define “natural.” True, breast milk is produced organically by the human body, and for most of human history, feeding infants at the breast was a fact of life. “Natural” also implies a process that is untainted by civilization and society, yet infant feeding practices have changed throughout history and vary by culture. When we think about breast-feeding, we imagine an infant at her mother’s breast. But in previous eras, mothers who could afford to do so enlisted other women (poor women, slaves, immigrants) to breast-feed their babies. This was the “natural” order of those cultures.

Also, when breast-feeding advocates say it is natural, often what they mean is that breast milk is wholesome. Yet it’s only as nutritious as the foods mothers eat, the air they breathe and the substances they consume. There are concerns that breast milk is tainted by environmental contaminants that nursing mothers cannot control, and women have been arrested for feeding their infants this “natural” substance after consuming drugs, alcohol and even prescription medications.

2. Formula is just as healthy as breast milk.

Infant-care experts made this claim throughout the 20th century. Some midcentury doctors even touted alternatives — made of cow’s milk whey or soy, along with oils, vitamins and minerals — as more nutritious than breast milk.It is not a coincidence that these alternatives are known as “formula,” a term that connotes scientific sophistication.

We now know that breast milk, with its unique balance of proteins, fats, vitamins and carbohydrates, confers a range of health benefits, including lessening the chances of ear infections, asthma, gastrointestinal ailments, diabetes, allergies, obesity and sudden infant death syndrome. But it is not clear that breast-feeding makes a substantial difference for children in developed countries. (There is no doubt about its advantages in places that lack access to clean water and adequate health care.)

Since scientists can’t assign women to randomized groups of breast-feeders and formula-feeders, they are forced to work backward from data, making it difficult to firmly establish whether breast-feeding improves a child’s health. For example, mothers who breast-feed are also more likely to adopt other wholesome behaviors: They eat less junk food, they’re less likely to smoke, and they see doctors. So studies have trouble determining whether children who were breast-fed are less likely to be obese because they received breast milk — or because their mothers cooked healthier foods.

3. One year is the optimal age for weaning.

Your average new mom will probably tell you she’s aiming to breast-feed for one year. That’s the recommendation of the American Academy of Pediatrics. But there’s nothing special about the one-year mark. In fact, there is no optimal age for weaning. Breast milk confers most of its advantages in the first three to four months of life, and some babies lose interest before their first birthday while others are happy to breast-feed well into toddlerhood.

The one-year goal reflects ambivalence about the breast in our hyper-sexualized culture: It is both a symbol of maternal care and the epitome of a woman’s sexuality. As babies grow teeth, begin to walk and talk, the sexual overshadows the maternal. Just witness the firestorm created by the recent Time Magazine cover that featured an almost-4-year-old at his mother’s breast.

4. Most American women breast-feed their babies.

Statistically, this is true. In 2011,75 percent of American mothers tried to breast-feed, and 35 percent continued to breast-feed exclusively at three months. But these numbers mask class and racial divides.

Among U.S.-born women, white, educated, older and married mothers are more likely to breast-feed. Low-income and minority mothers have fewer breast-feeding resources in their communities. And among some African Americans, breast-feeding has negative connotations dating to slavery, when slaves were purchased as wet nurses.

There are also economic barriers. Low-income women are less likely to get paid maternity leave and can’t afford lengthy unpaid leaves. Pumping — the magical solution to working mothers’ breast-feeding woes — is often not a viable option because it requires access to a clean, safe and private space; the opportunity to pump frequently; and a refrigerator to store breast milk. A little-known provision in President Obama’s health-care law requires most employers to provide breaks and a private room for nursing mothers, but implementation has been sluggish.

5. Breast-feeding rates dropped in the 20th century because more women entered the workforce.

In truth, U.S. breast-feeding rates began rising just as women entered the workforce in large numbers in the early 1970s. Since then, rates of breast-feeding and working women have grown in tandem.

Breast-feeding did decline dramatically after formula was introduced in the early 20th century. But women didn’t stop breast-feeding because they were too busy working. Formula’s early and enthusiastic adopters were white, middle-class mothers who didn’t work outside the home. And once formula was so closely associated with middle-class status, poor women were eager to embrace it.

Some women were ambivalent about breast-feeding, and pediatricians assured them that formula was an acceptable alternative. Others stopped because they were diagnosed with “insufficient milk syndrome,” a 20th-century epidemic largely created by doctors who recommended that mothers breast-feed according to a strict schedule (all the rage from the 1920s to the 1950s). We now know that adequate milk supply is attained when babies are fed “on demand,” though plenty of mothers have difficulty achieving and maintaining this equilibrium.

The women’s movement, which facilitated women’s entry to the workplace in the 1970s, was also instrumental in the resurgence of breast-feeding. “Our Bodies, Ourselves,” one of the movement’s best-known manifestos, celebrated breast-feeding as a subversive practice that affirms the natural capabilities of women’s bodies, defying doctors who discourage mothers from nursing.

avishai@fordham.edu

Orit Avishai is a sociology professor at Fordham University.

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Five myths about female voters

Five myths about independent voters

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