Why Breast Is Best

The Breastfeeding Book: Everything You Need to Know About Nursing Your Child
by Martha Sears, R. N., William Sears, M. D.

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.

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.

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.

© 2000 by Martha Sears, R.N., and William Sears, M.D.

About the Author

Martha Sears is a registered nurse, childbirth educator, and breastfeeding consultant.

William Sears, M.D., received his pediatric training at Harvard Medical School's Children's Hospital and Toronto's Hospital for Sick Children. He has practiced as a pediatrician for more than thirty years.