The Breastfeeding Book

COPYRIGHT © 2000 BY MARTHA SEARS, R.N., AND WILLIAM SEARS, M.D.

ALL RIGHTS RESERVED. EXCEPT AS PERMITTED UNDER THE U.S. COPYRIGHT ACT OF 1976, NO PART OF THIS PUBLICATION MAY BE REPRODUCED, DISTRIBUTED, OR TRANSMITTED IN ANY FORM OR BY ANY MEANS, OR STORED IN A DATABASE OR RETRIEVAL SYSTEM, WITHOUT THE PRIOR WRITTEN PERMISSION OF THE PUBLISHER.

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FIRST eBOOK EDITION: November 2008

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ISBN: 978-0-316-04752-4

Designed by Jeanne Abboud

Drawings by Deborah Maze

Also by William Sears, M.D., and Martha Sears, RN.

The Family Nutrition Book

The Pregnancy Book

(with Linda Hughey Holt, M.D., F.A.C.O.G.)

Parenting the Fussy Baby and High-Need Child

The Discipline Book

The Birth Book

The Baby Book

Nighttime Parenting

Becoming a Father

Also by William Sears, M.D.

The A.D.D. Book (with Lynda Thompson, Ph.D.)

SIDS: A Parent's Guide to Understanding and Preventing Sudden Infant Death Syndrome

Acknowledgments

WE WISH TO thank the many breastfeeding families who either directly or indirectly contributed to this book. A special thanks to the wise mothers of La Leche League International. This organization has provided mothers around the world with support and information about breastfeeding, correcting the myths and bad advice that have made breastfeeding difficult for many women. Because of La Leche League's efforts, the world is now more sensitive to the needs of mothers and babies. Much appreciation goes to two of our special teachers, Kittie Frantz, director of the Breastfeeding Clinic at the University of Southern California School of Medicine in Los Angeles; and Chele Marmet, director of the Lactation Institute in Encino, California. Bill had the privilege of working with Kittie for four years in pediatrics practice. Chele was Martha's teacher. Hugs and thanks go to our research assistants, Lisa Merasco and Tracee Zeni, for their conscientious help in preparing this book. We also wish to thank our editor, Jennifer Josephy, and our copyeditor, Pamela Marshall, who put the finishing touches on this book. Finally, this book Would not have been possible without our eight children, who taught us so much about the art of breastfeeding and how it helps express and shape that most tender relationship between mother and child.

1

Why Breast Is Best

IN THE EARLY DAYS of learning to breastfeed, there may be times when you feel like tossing in the nursing bra and reaching for a bottle. You may be tempted to believe those advisers who suggest that formula feeding is easier or just as good. Or you may worry that you're "not the type of mother" who succeeds at breastfeeding. Yet when you consider how breastfeeding benefits your baby, your family, and yourself, you will find the determination you need to overcome any obstacles and master the womanly art of breastfeeding. This chapter describes some of the innumerable ways that breastfeeding builds healthier brains, healthier bodies, and healthier families.

WHAT'S IN IT FOR BABY?

How would you like to give your baby a gift that could raise his IQ by 10 points; cut medical bills; make your baby's eyes, heart, intestines, and nearly every other organ work better; reduce the risk of life-shortening, debilitating diseases, such as diabetes; and help your baby avoid many of the common complaints of infancy, such as ear infections, tummy upsets, even diaper rash? What's the magic gift that can do all these things? Your milk! You can make your baby's life that much better simply by choosing to breastfeed.

Brighter Brains

Your baby's brain grows more during infancy than at any other time, doubling its volume and reaching around 60 percent of its adult size by one year. As with every system in the body, the better you feed the brain, the better it can grow. Breast milk is the best food for developing brains, and a flurry of brainy breast-milk research is now confirming what nursing mothers have long suspected: breastfed babies are smarter. A headline in USA Today in 1992 boasted "Mother's Milk: Food for Smarter Kids." Headlines such as this have renewed interest in the fact that breastfeeding is an important and often overlooked way to give a child, well, a head start. Scientific studies on the influence of breast milk on intellectual development conclude:

•    Children who were breastfed have IQ scores averaging 7 to 10 points higher than children who were formula fed.

•    The intellectual advantage gained from breastfeeding is greater the longer the baby is breastfed.

•    Intellectual differences between breastfed and formula-fed children that used to be attributed to the increased holding and interaction associated with breastfeeding and to the fact that mothers who breastfed were better educated and/or more child centered may be attributable to nutrients in breast milk that actually enhance brain growth.

YOUR MILK IS YOUR BABY'S MEDICINE

"Let food be your medicine," wrote Hippocrates. These words from the first doctor of medicine were not written about breast milk, but they are accurate in their description of it. Besides being the best preventive medicine for just about any disease, breast milk can also help cure an illness once it has started. This is particularly true of diarrheal diseases. The low mineral content of breast milk enables inflamed intestines to absorb the water in breast milk very efficiently. In addition, human milk contains anti-inflammatory substances and immune factors that help heal intestines rather than irritating them further as would happen with formula. This is why it has long been noted that not only do diarrheal illnesses occur less frequently in breastfed infants, but if they do occur, breastfed babies experience less dehydration and recover more quickly than formula-fed babies.

Other curative properties of breast milk come from the one million white blood cells contained in each drop of milk, which is why it is appropriately called "white blood." Breast milk has long been observed to help heal superficial infections, such as conjunctivitis. Try squirting some in the eye of a baby with conjunctivitis. (Express milk into a cup and use an eyedropper if your aim isn't so good.) It really helps.

The enteromammary immune system is another way mother's milk protects as well as nourishes her infant. When an infant is exposed to a germ, mother is often exposed to the same germ. But in the first six to nine months of life, the infant's ability to make antibodies to fight that germ is limited. So the mother makes these germ fighters for her baby, and these antibodies travel to her milk and are delivered to her baby. This system is especially helpful in fighting intestinal germs. Even when a baby contracts a germ, say at day care, the baby "exposes" mother's breasts to that germ through sucking, and within eight hours the breasts are able to make antibodies to that germ and offer them to the baby via the milk.

For years doctors told formula-feeding parents that by holding and interacting with their babies during feedings they could imitate breastfeeding, and their babies could then receive any intellectual or social benefits associated with breastfeeding. This was true to a point (it is better to hold the bottle and talk to your baby than to prop the bottle and walk away), but research is now showing that the smart stuff is in the milk, and it's not just the mothering that matters.

Smarter fats. What are these smart nutrients that are in mommy-made milk but not in milk from cows or the factory-made milk on the shelf at the store? One key ingredient is a brain-boosting fat called DHA (docosahexaenoic acid), an omega-3 fatty acid. DHA is one of several fats that have recently gotten a lot of attention as true health foods. DHA is considered a vital nutrient for the growth, development, and maintenance of brain tissue. Autopsy analysis of brain tissue from breastfed and formula-fed infants shows that the brains of breastfed babies have a higher concentration of DHA, and DHA levels are highest in babies who are breastfed the longest. This discovery is sending American formula manufacturers back to the drawing board, since at this writing infant formulas made in the United States do not contain DHA.

DHA and other fats in the breast milk contribute directly to brain growth by providing the right substances for manufacturing myelin, the fatty sheath that surrounds nerve fibers, insulating them so that these pathways can carry information. (As you will learn in chapter 4, a mother should supplement her diet with DHA-rich foods such as salmon and tuna or take DHA supplements daily in the form of capsules.)

Breast milk's role in the development of high-quality myelin and brain cells may play a role in the prevention of multiple sclerosis in adulthood. Research has shown that breastfeeding has a dose-related effect on the risk of multiple sclerosis. The longer the duration of breastfeeding, the lower the risk. The symptoms of multiple sclerosis are caused by myelin breakdown, and researchers speculate that a deficiency of omega-3 fatty acids in the myelin sheath makes the sheath more vulnerable to premature degeneration. Another explanation for breastfeeding's protective effect against degenerative nervous-system diseases is that the lower concentration of DHA in the brain-cell membranes of formula-fed infants could over a long period of time lead to defective brain-cell membranes, which allow easier entry of infectious or toxic substances into the brain cells.

Also, breast milk is rich in cholesterol; formula contains none. Cholesterol provides basic components for building the brain and manufacturing hormones and vitamin D. (Higher dietary cholesterol at the stage of fastest brain growth — what a smart idea!) Studies show that during the first year, exclusively breastfed infants have higher blood-cholesterol levels than formula-fed babies do. Depriving infants of sufficient amounts of this brain nutrient at a critical stage, as happens with formula, seems like a dumb idea.

BRAIN FATS VS. BODY FATS

In his book Smart Fats, Dr. Michael Schmidt points out that the type of fats needed to make a large body are different from those needed to make a large brain. Cows, for example, give milk to their calves that is high in saturated fats that encourage rapid body growth, but cow's milk is low in the fats that support rapid brain growth. The milk of each species is tailored toward the survival mechanism of that species. The calf runs for survival. This is why a calf's body grows rapidly in the first six months while its brain grows very slowly. Human beings must depend on their wits, so in human infants the brain grows quickly. To nourish this faster brain growth, human milk is rich in special long-chain polyunsaturated fatty acids (known as LC-PUFAs, pronounced "Elsie-Poofas") but low in saturated fats. A human baby's brain triples in size during the first year, but compared with the calf's, the body's growth is relatively slow.

Smarter sugars. The predominant sugar in breast milk is lactose, which the body breaks down into two simpler sugars, glucose and galactose. Galactose is a valuable nutrient for brain-tissue development. Anthropologists have demonstrated that the more intelligent species of mammals have greater amounts of lactose in their milk, and, not surprisingly, human milk contains one of the highest concentrations of lactose of any mammal's milk. Cow's milk and some cow's-milk formulas contain lactose, but not as much as human milk does. Soy-based and other lactose-free formulas contain no lactose at all, only table sugar and corn syrup. As we'll later discuss, lactose also promotes intestinal health.

Smarter connections. Brain cells, called neurons, resemble miles of tangled electrical wires. During the period of rapid brain growth in the first two years of life, these neurons proliferate and connect with other neurons to make circuits throughout the brain. The more circuits a baby's brain makes and the better the quality of these circuits, the smarter the baby. Every time a baby interacts with her caregivers, her brain makes new connections. Breastfed babies feed more often and are held more closely, with more skin-to-skin contact, so that each feeding is an opportunity to help the growing brain make the right connections, adding more circuits each time.

Leaner Adult Bodies

Breastfed infants become leaner adults. New research is discovering that leanness is associated with general health and well-being and with a lower risk of such diseases as heart disease, stroke, and diabetes. Studies have shown that children who were breastfed are less likely to be obese during adolescence, and that longer periods of breastfeeding greatly reduce the risk of being overweight later in childhood. Since overweight children are more likely to become overweight adults, preventing obesity in childhood is important. Lean means having just the right amount of body fat for an individual's body type. In 1992 the DARLING (Davis Area Research on Lactation, Infant Nutrition, and Growth) study from the University of California at Davis compared the growth patterns of healthy breastfed and formula-fed infants and found that breastfed infants were leaner at one year of age than their formula-fed counterparts. Even plump breastfed babies gradually lose a lot of their adorable baby fat and eventually wind up leaner than their formula-fed peers.

Why this difference? The amount of fat and calories in formula is about the same as in breast milk. The answer lies both in the type of fat and in the feeding method itself. As we discussed before, breast-milk fats, which are high in omega-3 fatty acids, are healthier fats. Also, breastfeeding gives infants the opportunity to control their fat intake themselves. The fat content of breast milk changes during a feeding to meet the needs of baby. If baby is simply thirsty or just needs some comfort sucking as a pick-me-up, baby sucks briefly for the foremilk, or "low-fat milk" that is stored right behind the nipple. If your baby is particularly hungry, baby sucks longer, stimulates mother's milk-ejection reflex, and gets the higher-fat hindmilk. Contrast this with the formula feeders. Regardless of whether baby is hungry, thirsty, or just needs to suck for comfort, he gets the same amount of fat whether he wants it or not.

Also, the fat content of mother's milk changes as the baby grows. The older infant needs fewer calories per pound of body weight than does the younger one, so by a wonderful quirk of nature, the level of fat in mother's milk gradually decreases to lower levels in the second half of the first year.

The satiety factor. Breastfed babies take smaller meals and eat more slowly. Eating patterns established in infancy reduce the tendency toward overeating later in life. Also, the high-fat milk that the baby receives toward the end of the feeding gives him a feeling of fullness. This and a satiety-producing hormone in the infant called cholecystokinin (CCK) condition the satisfied infant to stop eating. The breastfed baby himself controls how much he eats. You can't urge him to finish up the last 1/2 ounce at the breast the way a parent might when giving a bottle. A breastfed baby learns to trust his own signals about how much he needs to eat and when.

Better Eyes

Not only does breast milk build brighter brains and healthier bodies, it's valuable to baby's vision, too. Studies comparing breastfed and formula-fed infants show that visual development (in particular visual acuity) is better in breastfed babies. This finding is particularly noticeable in premature infants. Again, the smart fat DHA may be one of the reasons. DHA is one of the prime structural components of the retina of the eye. As with all tissues, the better you feed it, the better it grows and functions. So the better you feed the retina, the better the vision — another reason why breastfed babies have a healthier "outlook" on life.

Better Hearing

Not only do breastfed infants think, grow, and see better, but they are also likely to hear better. Being able to hear well is necessary for language development, so this benefit of breastfeeding is very important. The reason breastfeeding promotes healthier hearing is that breastfed babies have fewer ear infections. Because breast milk is a human substance, babies are not allergic to it (but they can be allergic to cow's-milk protein or other proteins in mother's diet that piggyback into the breast milk). Allergies to soy or cow's-milk proteins can cause fluid to build up behind the middle ear. This fluid not only dampens the vibration of the eardrum, decreasing hearing, it also provides a culture medium for bacteria and thus is a breeding ground for middle-ear infections. A history of frequent ear infections is common in children who are experiencing language delays.

A Nicer Smile

Pediatric dentists report that breastfed babies have better jaw alignment and are less likely to need orthodontic work. The sucking action used in breastfeeding involves more complex motions of the facial muscles and tongue. This improves the development of facial muscles, jawbones, and palate, leading to better jaw alignment and more room for teeth. The tongue-thrusting action bottle-fed infants use to control the flow of formula can contribute to malocclusion. Experienced pediatric dentists are often able to tell whether or not a baby was breastfed by the shape of the mouth and hard palate. Thus a baby's breastfeeding efforts will be reflected in her face.

Better Breathing

Another benefit pediatric dentists have noticed is that breastfed babies develop a larger nasal space, which can lessen problems with snoring and sleep apnea later in life. Breastfed babies grow a rounder, U-shaped dental arch, whereas bottle-fed babies develop a narrower, higher, V-shaped arch, which not only contributes to the misalignment of teeth but also infringes on the nasal passages directly above the hard palate.

Better Hearts

Formula is cholesterol-free, but you won't find formula manufacturers advertising this fact, even though you might expect a low-cholesterol diet to be good for babies — after all, many adults concerned with good nutrition try to limit their cholesterol intake. The cholesterol that is naturally present in cow's milk is removed during the formula-manufacturing process and replaced with fats from plant sources. Cholesterol is not only present in breast milk in moderate amounts, but it is most likely there for a heart-healthy reason. Some heart researchers theorize that a breastfed baby's liver learns to metabolize cholesterol better than a formula-fed infant's does. Breastfed babies may then have lower blood-cholesterol levels as adults and may thus enjoy a lower risk of heart disease. Supporting the heart-healthy theory, studies show that although breastfed infants tend to have higher blood-cholesterol levels than formula-fed babies do, adults who were formula fed as infants tend to have higher blood-cholesterol levels and be more likely to have atherosclerotic plaque that can lead to heart attacks.

Breastfeeding has an additional perk for infant hearts: the resting heart rates of breastfed babies are lower. The significance of this is unclear, but it could be a situation similar to the lower heart rate in the physically fit body of an athlete. A lower resting heart rate is an indicator of overall physical and emotional health.

Intestinal Health

Breast milk is known as the "easy in-easy out" food. It's easier to digest and makes easier-to-pass stools. In fact, breast milk contains enzymes that help babies digest their meals from the breast. Whey, the predominant protein in breast milk, forms an intestines-friendly, soft, easy-to-digest curd, unlike the rubbery, harder-to-digest casein curd formed in the digestion of most formulas. Tiny tummies like breast milk. It's digested more quickly and is less likely to come back up. It doesn't leave permanent stains on clothes, either.

While all babies spit up a bit, some regurgitate excessive amounts of milk because of a condition called gastroesophageal reflux (GER). Normally, the circular band of muscle where the esophagus joins the stomach acts like a one-way valve, keeping milk, food, and stomach acids from backing up into the esophagus when the stomach contracts. When it doesn't do its job, acids enter the esophagus, resulting in an irritation that adults would call heartburn. In many infants, it takes six months to a year for this muscle to mature enough to prevent this regurgitation or reflux. GER occurs less often in breastfed infants because breast milk is emptied twice as fast from the stomach and because breastfed babies tend to eat smaller meals that are more appropriate in size. It's less likely to be regurgitated than slow-to-digest formula with its tough casein curds.

Breast milk is friendly to immature intestines. The cells of the intestinal lining are tightly packed together so that potential allergens cannot seep through into the bloodstream. But in the early months, the lining of the baby's im-mature intestines is more like a sieve, allowing potential allergens to get through, which sets the infant and child up for allergies and infections. Breast milk contains a special protein called immunoglobulin A (IgA), which acts like a protective sealant in the digestive tract. Allergens and germs can't get through as easily. Breast milk also contains a special substance called epidermal growth factor (EGF), which promotes the growth of the cells lining baby's intestines as well as other surface cells, such as the cells of the skin.

Since formula does not provide this protective coating, it's easier for allergens to pass through into the bloodstream, a condition known as the leaky gut syndrome. This is part of the reason for the higher incidence of allergies in formula-fed infants. By the second half of the first year, the intestinal lining matures enough to prevent these leaks (a developmental process called closure).

Breast milk produces caregiver-friendly stools. Unlike the stinky stools of a formula-fed baby, the stools of a breastfed infant have a not unpleasant buttermilk-like odor. In watching moms and dads change the diapers of a formula-fed baby, we have noticed that their facial expressions generally reflect reactions that range from mild aversion to downright disgust. Because the odor of breast-milk stools is not offensive to most parents, changing the diaper of a breastfed infant is not an unpleasant task (which is fortunate, because younger breastfed babies have several bowel movements a day). When the baby looks at the face of the diaper-changing caregiver and sees happiness rather than disgust, he picks up a good message about himself — perhaps a perk for building self-esteem.

Breast milk helps better bugs live in the bowels. Intestines are healthier when you can keep the right bugs in the bowels, and that's exactly what breast milk does. The intestines contain healthful as well as potentially harmful bacteria. The healthful bacteria, known as bifidus bacteria, do good things for the body in return for a warm place to live. They manufacture vitamins and nutrients and keep the harmful bacteria in check. Breast milk promotes the growth of healthful bacteria and inhibits the growth of harmful ones. The high level of lactose in breast milk particularly encourages the growth of the healthful resident bacteria Lactobacillus bifidus.

Reduced Risk of Diabetes

Breastfeeding, plus the delayed introduction of cow's milk, reduces the risk of juvenile-onset diabetes. In addition, researchers have shown a lower insulin release in breastfed infants compared to infants fed formula. This preventive effect is particularly important for those who have a family history of diabetes.

Immunities

Your milk, like your blood, is a living substance. In the Koran, mother's milk is called white blood. A drop of breast milk contains around one million white blood cells. These cells, called macrophages (big eaters), gobble up germs. Breast milk is also power-packed with immunoglobulin A (IgA), which coats the lining of baby's immature intestines, helping prevent germs from leaking through. Colostrum, the "supermilk" you produce in the first few days, is especially rich in IgA, just at the time when a newborn is most susceptible to germs. Colostrum also contains higher amounts of white blood cells and other infection-fighting substances than does mature milk. Think of colostrom as your baby's first important immunization.

Filling the gap. Throughout the first six months, your baby's ability to produce his own antibodies to germs is somewhat limited. His immune system doesn't click into high gear until the second half of the first year. The maternal antibodies a baby receives through the placenta provide protection for a while, but antibodies gotten through the placenta are gradually used up during the first six months. Around six months of age, the influence of mother's antibodies is waning and baby's own antibodies are not yet at high levels. During this time, human milk's germ-fighting antibodies and white blood cells provide what's missing and protect baby from many of the germs in his environment.

The immune-boosting effects of breast milk are the reason behind the medical truism that doctors make their living on formula-fed infants. Studies comparing exclusively breastfed infants with formula-fed babies have shown that breastfed babies have lower rates of virtually every kind of infectious disease. This is all because of the protective effect of mother's milk, which can't be duplicated by factory-made formula.

Mother continually updates baby's immune protection. Because mother and baby are so close to each other, mother is exposed to the same environmental germs that a baby comes in contact with. The baby's immune system is too immature to respond quickly to germs, so mother's milk comes to the rescue. The mother's more mature immune system makes antibodies to the germs to which she and baby have been exposed, and this army of infection fighters enters her milk and eventually her baby.

IMMUNIZE YOUR BABY EVERY DAY! BREASTFEED

Motto of the International Lactation Consultant Association

Healthier skin