January 2019 Issue

Infant Nutrition: Breast Milk Benefits
By Sherry Coleman Collins, MS, RDN, LD
Today's Dietitian
Vol. 21, No. 1, P. 18

It's still the best source of nutrients for babies.

According to the most recently available statistics from the Centers for Disease Control and Prevention, in 2013 about 80% of mothers breast-fed their babies at birth. However, at six months, nearly one-half had discontinued breast-feeding, and less than one-third were still breast-feeding at 12 months.1 Guidelines from the American Academy of Pediatrics (AAP) state that mothers should breast-feed exclusively for the first six months and for at least 12 months total, recommendations echoed by the Academy of Nutrition and Dietetics.2,3 This article reviews the benefits of breast-feeding to baby and mother, barriers to initiating and continuing breast-feeding, and the RD's role in supporting breast-feeding.

Healthful for Baby and Mother
There's no question that breast-feeding benefits both mother and baby. Science has proven time and again that breast milk is a complex, changing, and ideal form of nutrition for growing babies. There's high variability associated with breast milk based on several factors including the mother's diet, body stores of nutrients, and environmental exposure, among others.4 "Breast milk is easier for babies to digest, and, depending on moms' diets, has all the nutrients and other substances infants need to help protect against infections—and it benefits mothers' health, too," says Elizabeth Ward, MS, RD, a Boston-based dietitian and author of Expect the Best: Your Guide to Healthy Eating Before, During, and After Pregnancy. "Breast-feeding is free, convenient, and there is no formula to make or bottles to wash."

The macronutrient composition of breast milk varies by the age of the baby at delivery; it changes over the duration of breast-feeding and even by time of the day.4 Hindmilk, the last part of the milk expressed in a feed, is known to be highest in fat. In this way, breast milk transforms to what a baby needs and when. According to Jess Collet, MS, RDN, a certified lactation counselor and owner of The Blended Life in Atlanta, "Colostrum, known as 'liquid gold' due to its yellow color and health properties, is produced in the first few days. It's loaded with white blood cells and antibodies, laying down a strong foundation for the infant's immunity. Colostrum also helps the infant clear certain wastes, especially bilirubin, which can lead to jaundice, and meconium, the first stool." In fact, babies receive some of their mother's immunity via these and other bioactive components of breast milk, which provides protection against disease and infection. Macrophages and stem cells, immunoglobulins, cytokines and chemokines, and antimicrobial factors are present in breast milk. Hormones, growth factors, oligosaccharides and glycans, and mucins also are present and support a variety of immune functions and protect against illness and disease.4

Human milk oligosaccharides (HMOs) are abundant in breast milk. HMOs are bioactive prebiotics that support healthy microbiota colonization in the gut and intestinal mucosa.5 HMOs pass through the infant gastrointestinal tract undigested to feed gut bacteria. This may be one of the reasons that breast-fed infants are known to have a more diverse microbiota than those fed infant formula. "We know that HMOs selectively promote the growth of beneficial bacteria while suppressing certain pathogens in the infant gut," Ward says. So beneficial are HMOs in breast milk that some infant formula companies are now working to incorporate them into formula.

Short-term benefits to the mother may include more weight loss after delivery and help returning women to prepregnancy weight more quickly.6 In addition, hormones associated with breast-feeding cause the uterus to contract back to its prepregnancy size and reduce the risk of uterine hemorrhage.7 Breast-feeding also delays the return of menses, which can reduce the chance of becoming pregnant again too soon.

Babies who are breast-fed have lower rates of ear and gastrointestinal infections, eczema, and asthma and respiratory infections. Breast-feeding also reduces the risk of sudden infant death syndrome.1 In preterm and low birth weight babies, breast milk can help decrease the risk of developing necrotizing enterocolitis.1,8 "Breast milk is easier to digest and lowers the risk of compromising the intestinal tract, which can be disrupted by proteins in cow's milk-based formulas," Collet says about these tiniest of babies.

Researchers still are learning about the long-term benefits of breast-feeding, yet there are promising associations. Women who breast-feed have lower risk of breast and ovarian cancers, type 2 diabetes, and hypertension.1,8 Children who were breast-fed as infants have lower risk of conditions such as type 2 diabetes, inflammatory bowel disease, and obesity, with a 26% reduction associated with longer-term breast-feeding.1,8 There's even some evidence that breast-feeding is associated with a higher IQ of around three points.8 According to an expert panel, breast-feeding represents personalized medicine "at a time when gene expression is being fine-tuned for life."8

Barriers to Breast-Feeding
Although it seems that breast-feeding should be intuitive and easy, it isn't always the case. In fact, there are a variety of conditions that can make breast-feeding feel impossible to the sleep-deprived nursing mother. Conditions such as mastitis, poor milk supply, and anatomical differences such as inverted nipples may require intervention and help for women to successfully breast-feed. In addition, babies with sensitive gastrointestinal systems or protein intolerances may require mothers to temporarily adopt dietary modifications, although mothers' diets don't need to be limited in most cases.

The health care provider's attitude can have a significant impact on breast-feeding success. In one review, conversations between patients and providers about breast-feeding often were perceived by patients as ambivalent, short, and lacking the necessary education to become confident nursing mothers.9 Health care providers, particularly pediatricians and women's health professionals, should be aware of the benefits of breast-feeding and how they can assist in supporting mothers' decisions to nurse. The same support is important from families, partners, and spouses.

Not all companies or jobs provide the most supportive environment for ongoing breast-feeding. However, the Affordable Care Act requires employers with more than 50 employees to provide support for breast-feeding mothers for one year after each subsequent delivery. The law requires "reasonable break time and a private, nonbathroom space" to express milk.1 Work can be stressful on any sleep-deprived person, but even more for the breast-feeding mother, making support in the professional environment essential.

If travel is required, the hassle and extra stress of carrying all of the equipment necessary to express milk while away from home may be daunting. The Transportation Security Administration allows breast milk, formula, ice packs, and other needed accessories to be transported in carry-on bags. Liquids are X-rayed for safety.

Some women are hesitant to breast-feed in public, and it's not always convenient or possible to find a completely private location. "It's unfortunate that some women have been frowned upon while breast-feeding in public or asked to leave certain venues," Collet says. "We need to normalize breast-feeding." All 50 states, the District of Columbia, Puerto Rico, and the Virgin Islands have laws that specifically allow women to breast-feed in any public or private location.1

Critical Caveats
While there's no doubt that breast milk is nutritionally superior to infant formula, there are some important caveats to keep in mind. While breast milk is uniquely nutritious, the AAP recommends supplementing infants with 400 IU of vitamin D and 1 mg/kg/day of iron (until iron-fortified foods are added to the baby's diet) starting shortly after birth to reduce the risk of deficiencies.10

Complementary foods should be added to the diets of infants aged 6 months for added nutrition, to teach proper feeding skills, and encourage healthful eating behaviors. Allergens also should be included in the first year, with peanut-containing foods started as early as age 4 to 6 months to reduce the risk of peanut allergy. The National Institute of Allergy and Infectious Diseases' guidelines provide excellent information on when and how to safely introduce peanut foods for peanut allergy prevention.11 Mothers who breast-feed past 12 months should know that it's associated with an increase in dental caries in infants, possibly due to inadequate oral hygiene after feeding, and should be counseled on dental care for the infant and toddler.8

Finally, in the event that a mother can't or chooses not to breast-feed, she should be supported in finding the best infant formula for her child's needs and assured that infant formula is a safe and nutritious choice. "I like to talk about the benefits of breast-feeding, but never in a way that makes women feel guilty for using infant formula," Ward says. "Fed is best, and infant formula is better than ever."

The Dietitian's Role
RDs can support breast-feeding in many ways. They can empower women through nutrition education to embrace all of the benefits to themselves and babies and overcome barriers. They can provide referrals to certified lactation counselors and support groups, advocate for legislation and programs to make breast-feeding easier for mothers and normalized in all environments, and educate new mothers about their rights (state by state).

Dietitians can help new mothers maintain adequate nutrition. In addition to eating enough calories and protein, sufficient fluid should be consumed each day to support milk production. Mothers need to eat enough food with variety necessary to achieve adequate daily vitamins and minerals for themselves and to provide for their children. Some mothers may need education to gain access to WIC, the Supplemental Nutrition Assistance Program, or local food pantries, to address food insecurity. Protein, fat, and long-chain fatty acids such as omega-3 and omega-6 in breast milk are regulated by the mother's diet.4 Many will have questions about dietary supplements and over-the-counter medications, and dietitians can offer guidance.

The evidence for the health benefits of breast-feeding for both women and infants is compelling, yet breast-feeding rates in the United States are low. Both Ward and Collet stress the role RDs can have as encouragers in addition to counselors. Dietitians can provide evidence-based information, instruction, and insight, with a powerful dose of emotional intelligence to support every breast-feeding mother on her journey.

— Sherry Coleman Collins, MS, RDN, LD, is president of Southern Fried Nutrition Services in Atlanta, specializing in food allergies and sensitivities, digestive disorders, and nutrition communications. Find her on Twitter, Instagram, and Facebook as @DietitianSherry, via the Southern Fried Girlfriends podcast, and at www.southernfriednutrition.com.

1. Breastfeeding report card: progressing toward national breastfeeding goals — United States, 2016. Centers for Disease Control and Prevention website. https://www.cdc.gov/breastfeeding/pdf/2016breastfeedingreportcard.pdf. Published August 2016. Accessed November 12, 2018.

2. Section on breastfeeding. Breastfeeding and the use of human milk. Pediatrics. 2012;129(3):e827-e841.

3. Lessen R, Kavanagh K. Position of the Academy of Nutrition and Dietetics: promoting and supporting breastfeeding. J Acad Nutr Diet. 2015;115(3):444-449.

4. Ballard O, Morrow AL. Human milk composition: nutrients and bioactive factors. Pediatr Clin North Am. 2013;60(1):49-74.

5. Fanos V, Reali A, Marcialis MA, Bardanzellu F. What you have to know about human milk oligosaccharides. J Pediatr Neonat Individual Med. 2018;7(1):e070137.

6. Jarlenski MP, Bennett WL, Bleich SN, Barry CL, Stuart EA. Effects of breastfeeding on postpartum weight loss among U.S. women. Prev Med. 2014;69:146-150.

7. Haxton D, Doering J, Gingras L, Kelly L. Implementing skin-to-skin contact at birth using the Iowa model: applying evidence to practice. Nurs Womens Health. 2012;16(3):220-229.

8. Victora CG, Bahl R, Barros A, et al. Breastfeeding in the 21st century: epidemiology, mechanisms, and lifelong effect. Lancet. 2016;387(10017):475-490.

9. Lee E, Jackson J. Breastfeeding knowledge and intent to breastfeed: an integrative review. Clin Lactation. 2016;7(2):62-68.

10. Vitamin D & iron supplementation for babies: AAP recommendations. HealthyChildren.org website. https://www.healthychildren.org/English/ages-stages/baby/feeding-nutrition/Pages/Vitamin-Iron-Supplements.aspx. Updated May 27, 2016. Accessed November 12, 2018.

11. Togias A, Cooper SF, Acebal ML, et al. Addendum guidelines for the prevention of peanut allergy in the United States: report of the National Institute of Allergy and Infectious Diseases-sponsored expert panel. https://www.niaid.nih.gov/sites/default/files/addendum-peanut-allergy-prevention-guidelines.pdf. Published 2017. Accessed November 12, 2018.