Alicia Dermer, M.D., I.B.C.L.C.
Anne Montgomery, M.D.

Human Milk's Nutritional Benefits
Human milk, the best food for babies, contains the right amount of nutrients, in the right proportions, for the growing baby. A living, biological fluid, it contains many unique components. For example, lactoferrin provides optimal absorption of iron and protects the gut from harmful bacteria; lipases assist in digestion of fats; and special growth factors and hormones contribute to optimal growth and development. Mother's own milk changes during a feeding from thirst-quenching to hunger-satisfying, and comes in a variety of flavors as mother's diet varies. Its composition changes as the baby grows to meet baby's changing nutritional needs. It serves as the nutritional model for artificial baby milks, but none of these can match it.

While most people are aware that human milk provides excellent nutrition, many people are unaware of breastfeeding's other health benefits for babies.

Breastfeeding and the Immune System
Human milk is baby's first immunization. It provides antibodies which protect baby from many common respiratory and intestinal diseases, and also contains living immune cells. First milk, colostrum, is packed with components which increase immunity and protect the newborn's intestines. Artificially fed babies have higher rates of middle ear infections, pneumonia, and cases of gastroenteritis (stomach flu). Breastfeeding as an infant also provides protection from developing immune system cancers such as lymphoma, bowel diseases such as Crohn's disease and celiac sprue, and juvenile rheumatoid arthritis, all of which are related to immune system function. And breastfed babies generally mount a more effective response to childhood immunizations. In all these cases, benefits begin immediately, and increase with increasing duration of breastfeeding.

Babies from families with a tendency to allergic diseases particularly benefit from breastfeeding. Exclusive breastfeeding, especially if it continues for at least six months, provides protection against allergies, asthma, and eczema.

Infant Growth and Development
New growth charts from the World Health Organization confirm that breastfed infants grow differently from formula fed babies. Breastfed infants grow faster initially, then slow down as they approach their first birthday.(This can sometimes be interpreted as "dropping off the growth curve," but really represents normal growth.) People artificially fed as infants go on to have a higher risk of obesity as adults.

More and more research is showing that breastfeeding leads to optimal brain development. While there are behavioral aspects to this, the milk is important, too. One study of premature babies who were tube-fed breast milk or artificial milk, but were never breastfed directly, showed that the babies who received no breast milk had IQS 8 points lower on average than those who received breast milk. Human milk has special ingredients like DHA (docosohexaenoic acid) and AA (arachidonic acid) which contribute to brain and retinal development. And all breastfed babies tend to spend a lot of their time in the "quiet alert" state which is most conducive to learning.

Breastfeeding in Special Circumstances
Breastfeeding has other special benefits for premature infants. Premature breastmilk contains different amounts of some nutrients than term breastmilk, more suited to the needs of premature babies. Necrotizing Enterocolitis, a serious bowel inflammation, is very rare for breastfed infants. And of course they get the same immune protection, which may be even more critical for prematures, and has been shown to reduce the risk of sepsis in these babies. Suckling at the breast, and digesting breast milk, cause less stress for the premature infant than bottle-feeding does; so most prematures can go to breast as soon as they are able to suckle. Because of the reduction in infections and the shorter time to full feeding, breastfed premature infants can usually leave the NICU sooner. For some babies, breastfeeding is a life-and-death matter. In addition to its known benefit where water supplies are unsafe or food supplies erratic, breastfeeding lowers the risk of SIDS in all populations.

There are very few reasons, particularly from the baby's point of view, to avoid breastfeeding. Most authorities recommend that USA mothers who are HIV positive not breastfeed; however, in many areas of the world breastfeeding's known benefits outweigh the small risk of transmission from breast milk. Few other medical conditions preclude breastfeeding, as there are many appropriate medications that are suitable for use in breastfeeding moms.

Breastfeeding's immunologic and developmental benefits may be particularly important for babies with medical problems such as congenital heart disease, cleft palate, Down's syndrome, etc. In cases where the baby has a problem which affects ability to suckle at the breast, expressed breast milk from mother is still the best choice. Banked human milk, the availability of which is unfortunately limited, would be the second choice. Commercial artificial baby milks are preferable to other alternatives, but far from perfect substitutes for human milk. For every "new" component that is added to commercial baby milks to make them closer to human milk, several more components of human milk are discovered.

It's not JUST the milk, either!
In addition to all the known benefits of human milk, it's also clear that the act of breastfeeding is beneficial. Breastfeeding's contribution to optimal oral development means less risk of malocclusion -- and perhaps lower orthodontist bills! Bottle-fed babies have a higher risk of baby bottle tooth decay, as well. Close skin-to-skin contact with mother provides optimal nurturing and an almost automatic close emotional attachment. Suckling at breast optimizes hand-to-eye coordination, especially with regular "side-switching." Even in the rare cases when mother can't produce enough milk, or for adopted babies, supplemental systems can allow mother and baby to enjoy a breastfeeding relationship.

Breastfeeding and Women's Health
The extent to which breastfeeding affects mothers' health is rarely emphasized. Much of the lay literature about breastfeeding makes it sound like a rather time-consuming, difficult and even painful experience that women must endure for the sake of their babies' health. No wonder some mothers are left with the impression that they must "martyr" themselves and breastfeed for their baby's sake.

Surprise: Breastfeeding is good for mothers, too! Not only that, but it is a joyful, relaxing experience. Although breastfeeding advocates have been criticized for oversimplifying and not informing mothers of potential problems of breastfeeding, the truth of the matter is that when practiced optimally breastfeeding is an enjoyable experience, pure and simple. We must remember that many of the problems and inconveniences so commonly described in the lay literature and passed around by word of mouth as "horror stories" are due to the fact that we live in a bottle-feeding society, with little family or social support and little understanding of breastfeeding by many health care professionals. Thus, problems such as "insufficient milk syndrome," engorgement, cracked and bleeding nipples, all of which would be rare in a breastfeeding society, have become commonplace.

Physical Health Benefits for Mothers
First of all, it almost goes without saying, but what's good for babies is good for mothers. In other words, healthier babies are less stressful to care for, and the decreased medical costs are a boon to the family. Furthermore, the optimal neurological and intellectual development provide potential long-term benefits to the family.

In addition, there are many direct health benefits to breastfeeding mothers. Immediately after birth, repeated bursts of oxytocin released in response to the baby's sucking cause contraction of the uterus. This protects mothers from postpartum hemorrhage (bottle-feeding mothers get oxytocin intravenously immediately after birth, but for the next 24-48 hours during which risk of hemorrhage is highest, they're on their own). Continued exclusive nursing (i.e., breastfeeding without added bottles of formula or solids) tends to delay the return of ovulation and menstruation. In fact, the lactational amenorrhea method (LAM) is a well-studied method of child spacing which is 99% effective in preventing pregnancy in the first six months as long as exclusive nursing is practiced. For mothers who don't practice exclusive breastfeeding, there is still some relative protection; and most contraceptives including barrier methods, IUD's and even progesterone-only hormonal contraceptives such as the "mini-pill" or injectable "depo" progesterone, are all compatible with breastfeeding. So there's no need to stop breastfeeding in order to use effective birth control.

In addition to the child-spacing advantage, the delayed menses also decrease the mother's iron losses. When combined with improved iron absorption from the gut, the net effect (despite some iron use for breastmilk production) is decreased risk of iron deficiency anemia.

Another well-documented benefit of breastfeeding is more rapid and sustained weight loss. Milk production uses up 200-500 calories a day. To burn off an equivalent number of calories, a bottle-feeding mother would need to swim 30 laps or ride a bicycle for over an hour. In our opinion, breastfeeding is definitely easier! Mothers who have had gestational diabetes benefit particularly from the efficient use of calories during breastfeeding, since a return to optimal weight may prevent subsequent development of diabetes. Furthermore, diabetic mothers who breastfeed tend to need less insulin or medication for their diabetes.

The prolonged suppression of ovulatory cycles appears to be associated with significant long-term health advantages as well. Mothers who breastfeed for at least 6 months throughout their lifetime have a decreased risk of breast cancer, and similar reduced rates have been shown for ovarian and uterine cancers. Even being breastfed has been associated with decreased risk of breast cancer, over and above the fact that women who were breastfed themselves are more likely to breastfeed their own children.

For some time, there was concern about calcium loss during lactation and potential for osteoporosis. In fact, some literature actually lists breastfeeding as a risk factor for osteoporosis. Current medical literature demonstrates that not only is the loss in bone density during breastfeeding temporary, reverting to normal after weaning, but that bones may actually be stronger after prolonged breastfeeding. Far from a risk factor for osteoporosis, breastfeeding may actually protect against it.

The impact of breastfeeding on other women's illnesses needs further study. One example is the connection between breastfeeding and cholesterol levels. Breastfeeding mothers tend to have high total cholesterol levels, made up largely of the HDL ("good") fraction. This may prove to decrease the risk of coronary artery disease.

Are there any known harmful effects of breastfeeding on women's health? A couple of studies have demonstrated an increased risk of rheumatoid arthritis flare-ups and increased severity of arthritis in nursing mothers. Whether it is breastfeeding or some other confounding factor which causes this increase remains to be determined.

Psychosocial Issues in Breastfeeding and Women's Health
What about the emotional aspect of women's health? Where does breastfeeding fit in? Let's talk about mother-infant bonding, a somewhat controversial subject. Much is made about the way that breastfeeding facilitates this bonding, while at the same time it is clear that bottle-feeding mothers usually establish deep emotional bonds with their babies. This issue is difficult to study scientifically, but there is evidence of hormonal effects of breastfeeding which may predispose a mother to closer bonding with her infant. Combined with the automatic skin-to-skin contact and closeness afforded by breastfeeding (something which bottle-feeding mothers have to work to duplicate), this could result in improved bonding. An interesting sideline from a study in a developing country found that when breastfeeding rates were increased among mothers with a significant abandonment rate, fewer of these mothers abandoned their babies. Other studies have suggested that there may be a lower rate of child abuse in breastfeeding families considered to be at risk.

Another common psychological issue after birth is postpartum depression(PPD). The role of breastfeeding in this area is not clear, with some studies showing increased rates of PPD among breastfeeding mothers, others lower rates. The cause of PPD is unknown, and is probably due to a number of factors, including hormonal changes and lack of support in the new overwhelming role of motherhood. For some depressed mothers, their breastfeeding relationship takes on special importance. Sometimes, when antidepressant medications are deemed necessary, doctors are concerned about prescribing them for a breastfeeding mother. Antidepressants have been studied, and some have been demonstrated not to get to the baby or cause any symptoms. The small potential risk of the medication to the baby has to be weighed against the potential emotional devastation to an already depressed mother of having to wean her baby, as well as the known detrimental effects on infant emotional development when mother suffers from persistent depression.

Let's consider the situation of mothers who need to return to work. Is it worth it to breastfeed at all? Is it necessary to wean the baby when returning to work? Is pumping and storing mother's milk worth the effort? The answer to these questions is: yes, no and definitely. Even if a mother needs to return to work within weeks and will be unable to pump while at work, the baby benefits from the colostrum and early milk and mother gets the experience of the closeness and bonding. On return to work, a breastfeeding mother has three options: continue to breastfeed exclusively by nursing while at home and pumping her milk while at work; continue to nurse while at home and feed formula while at work; wean completely to formula. Clearly, any amount of continued breastfeeding would be preferable to weaning. Studies have shown that babies in day care whose mothers provide their milk have the fewest days out of day care and their mothers have the fewest missed days from work, while those who were breastfed and got some formula were sick more often. The mothers of completely formula-fed babies had the most days out of work to care for their sick babies.

Although pumping and storing may sound daunting and time-consuming, most mothers whose employers give breastfeeding support find that they work into an easy routine, and the work of pumping is worth it for the peace of mind of a healthier child and the continued bonding from breastfeeding on returning home. Increasing numbers of companies, in response to studies showing economic benefits, are instituting policies supportive of continued breastfeeding for their employees. Additionally, the cost of renting or even purchasing a pump is much lower than the cost of formula.

Breastfeeding and Fathers
So what's in it for Dad? Breastfeeding benefits fathers, too. First, and most straightforward, breastfed babies have less offensive dirty diapers. There are no bottles to prepare and warm in the middle of the night. Fathers benefit from having a healthy baby, and can play with, snuggle, and bathe the baby as their relationship develops. If participating in feeding is important, he can be the main solid-food feeder later. Dads generally also appreciate the impact on the family budget of lower health care costs, fewer sick days, and lack of need to buy formula. And all of the health benefits for mothers make it likely that his partner will be healthier.

Breastfeeding and The Environment
Another important issue related to infant feeding and health is the interaction between infant feeding method and the environment. Breastfeeding is a completely natural, efficient use of resources. In contrast, artificial feeding involves overgrazing of land by cattle; use of chemical fertilizers to grow the soy; use of valuable environmental resources for formula production; packaging and transportation of the product; use of water and fuel for mixing the product and heating it, for sterilizing bottles and nipples; waste disposal of the cans, bottles, accessories, cartons, etc.

Despite this, the media and some environmental groups tend to play up issues of environmental contaminants in mother's milk. In fact, except in situations of toxic spills or occupational exposure to hazardous levels, breastfeeding has caused no ill effects in babies. To the contrary, studies comparing breastfed and bottle-fed babies in the same environment have shown better development and less cancer in the breastfed babies.

Furthermore, despite concerns about PCBs in breastmilk potentially producing infertility in the offspring, the major burden of PCBs gets to babies during pregnancy. (Note: cows get exposed to PCBs, too, so artificial milks are not necessarily "pure," either.) A lesser known and less publicized issue is the fact that soy formulas contain phytoestrogens, which may have just as serious long-term effects. Rather than calling for women to avoid breastfeeding, the call needs to be to continue to clean up the environment to safeguard everyone's health. Breastfeeding will contribute to this clean-up effort.

Conclusion
In light of the overwhelming evidence of breastfeeding benefits not only for babies but also for mothers and the planet, it seems fair to say that the choice of an infant feeding method is far more than the choice between two relatively similar methods with only convenience as the deciding factor. When a mother chooses not to breastfeed or decides to wean early from the breast, she is not merely substituting an inferior artificial substance without any disease-protection properties for her child and feeding her child with an unnatural implement. She is also potentially affecting her own immediate and long-term health in many ways. Artificial feeding increases personal and societal health care costs, and detrimentally affects the environment.

Breastfeeding in a society where bottle-feeding is the norm clearly requires a significant commitment, especially when relatives and friends do not support breastfeeding. However, women making the decision about infant feeding should know that breastfeeding is clearly more than a lifestyle choice: it is a significant health decision with life-long consequences. And, speaking from personal experience, it's also fun!

Editor's note: Alicia Dermer, M.D., I.B.C.L.C. is Clinical Assistant Professor in the Department of Family Medicine at the University of Medicine and Dentistry of New Jersey -- Robert Wood Johnson Medical School. She is board certified in Family Practice.

As part of her interest in wellness and health promotion, Dr. Dermer has developed a special interest in the area of breastfeeding education and promotion. She is active in educating health care professionals, especially fellow physicians, in lactation. She is collaborating on the development of a curriculum for her medical school. In 1995, she successfully passed the certifying examination of the International Board of Lactation Consultant Examiners. She has published medical journal articles on lactation, and lectures extensively on the subject. She may be contacted at: Alicia Dermer, MD, IBCLC, 69 County Road 516, Old Bridge, New Jersey 08857 USA, Telephone: (908) 254-1515; FAX: (908)651-0774, e-mail: dermer@umdnj.edu

Anne Montgomery, M.D. is a board certified family physician, and Clinical Assistant Professor in the department of Family Practice at the University of Washington. She teaches family practice residents and medical students at the St. Peter Hospital Family Practice residency. She is a fellow of the American Academy of Family Physicians, a member of the Academy of Breastfeeding Medicine, and a supporting member of the International Lactation Consultants Association. She is active in birth and breastfeeding advocacy, and lectures frequently on these subjects.

She was in private practice for 5 years in Minnesota, after graduating from Mayo Medical School, and completing her residency in family practice at St. John's Unit of the University of Minnesota Community Hospital's family practice training program. Dr. Montgomery is married to Charles Nordstrom, and the mother of Ian Montgomery Nordstrom, a breastfed baby who is now 6 years old.

She may be contacted at: Anne Montgomery, M.D., St. Peter Hospital Family Practice Residency, 525 Lilly Road NE, Olympia, Washington USA 98506, telephone: (360) 493-4040, e-mail: annemont@u.washington.edu

© February 1, 1997, Joel R. Cooper, All rights reserved