Last month, I described how the term superfood is used as a marketing tool and has no scientific, legal or regulatory definition1. In this issue, I want to propose that the only true superfood is mother’s breast milk.
The World Health Organization (WHO)2, American Academy of Pediatrics3 and U.S. Department of Health and Human Services4 have all recommended breastfeeding for at least the first six months of life and including it in a mixed diet for at least until the infant is two years old. So, the aim of this article is to describe the many health benefits of breast feeding.
Breastfeeding is good for both the mother and her babies. It helps them form a strong, loving bond that can last a lifetime and help during difficult times later in life. Moreover, mother’s milk meets the baby’s nutritional needs. It contains bioactive peptides and proteins5, as well as growth factors, hormones, lipids and carbohydrates6,7. Breast milk is vital in protecting infants from neonatal sepsis and stimulating immunity, while promoting growth and development6,7. Human milk also contains white blood cells that stimulate an infant’s immunity. They help to prevent allergies and enhance the baby’s intestinal development. Mother’s milk also contains many specific proteins that provide additional protection from infection7.
Milk is often classified into colostrum, transitional milk and mature milk6. However, these are not distinct classes of milk, but refer to the gradual changes in the content of milk throughout lactation. Colostrum, the first milk produced, is quite different from mature milk. It contains high concentrations of whey protein, while caseins are almost undetectable. The average content of protein in breast milk gradually decreases from the second month to the seventh month, after which the concentration of protein levels off.
Colostrum contains low concentrations of both lactose and fat compared to mature milk. There is a gradual increase in the concentration of fat the beginning, known as foremilk, to the end of a feeding, hind milk, while lactose shows an inverse correlation to the change in fat content. There is a diurnal variation in the concentration of milk fat, with a peak at midmorning and a low overnight, varying from about 5 g/100 mL to about 3 g/100 mL. Lactose production is highest in the fourth to seventh month, after which it decreases, while a gradual increase in the concentration of lipids occurs6.
Lipids are the largest source of energy in breast milk6. There are also short-chain fatty acids (SCFA) in breast milk. They are also essential for proper maturation of the baby’s gastrointestinal tract. There are also sphingomyelins that are especially important for forming myelin sheaths for neurons in the Central Nervous System (CNS). They can help improve the neurobehavioral development of infants who have a low body weight at birth. Breast milk lipids can also inactivate various pathogenic bacteria, such as Group B Streptococcus (GBS).
Breast milk also contains over 400 different proteins which provide nutrition and have antimicrobial as well as immunomodulatory activities, while stimulating the absorption of nutrients. The antibodies found in breast milk target the infectious agents encountered by the mother immediately before and after birth, as well as the infectious agents most likely to be encountered by the baby6.
There are also many complex carbohydrates in milk, as well as the disaccharide, lactose6. Human milk has a higher concentration of lactose than any other species, due to the high energy demands of the human brain. There are also human milk oligosaccharides (HMO) that babies can’t digest. Instead, they nourish the healthy bacteria in the baby’s gut (the gastrointestinal microbiota). HMOs encourage the growth of beneficial bacteria, such as Bifidobacterium infantis in the baby’s GIT. This protects the baby from being colonized by pathogenic bacteria. So, HMOs help prevent neonatal diarrhea and respiratory tract infections6.
In addition, breast milk contains a diverse community of healthy bacteria. The bioactive molecules in breast milk guide the development a healthy gut microbiome6. Before an adult can have a healthy, diverse gut microbiome and brain, he or she must have a healthy fetal, neonatal and infant microbiome8. The gut microbiome affects the development of the brain. It is especially important for the formation of synapses that connect neurons with the blood-brain barrier, as well as the proper function of microglia that support neurons. Many of the metabolites produced by gut bacteria are important in the development of the young brain. The gut microbiome is also important for priming the innate immune system in both the peripheral and central nervous systems. The mother’s breast milk contains oligosaccharides that stimulate the growth of beneficial communities of bacteria, including Bifidobacterium species. This leads to better cognitive development of the baby. In contrast, prenatal stress can cause an unhealthy imbalance in the baby’s gut microbiome. Moreover, children with neurodevelopment disorders, such as ASD often have an unbalanced gut microbiome that can lead to atypical patterns of connectivity between the cells in the brain. HMOs are especially important in ensuring the proper development of the baby’s microbiome6-9.
Mother’s milk also contains healthy bacteria that colonize her baby’s gut during breastfeeding and establish the baby’s healthy microbiome. Human milk contains about 400 different species of bacteria10. They establish colonies of helpful bacteria (including Staphylococcus and Streptococcus species) that help prevent the baby’s gut from being colonized by other, pathogenic bacteria and help make flu (influenza) vaccines more effective. In addition, mother’s milk contains pioneering colonizers such as Bifidobacterium longum that carry several gene clusters that enable babies to metabolize HMOs. This allows infants to digest breast milk11. These HMOs also help prevent infection by pathogenic bacteria12. HMOs are different than the oligosaccharides that are in other mammals. This is one reason why breastfeeding is better than formula. HMOs also act as prebiotics to stimulate the growth of healthy bacteria in a baby’s gut. They also prevent the adhesion of harmful bacteria and act as receptor decoys that keep pathogenic bacteria from colonizing mucosal surfaces. They are especially useful in preventing the growth of Streptococcus agalactiae, more often known as Group B Streptococcus (GBS). It’s a common cause of neonatal sepsis and meningitis. HMOs also help keep GBS from forming biofilms that would protect them from the infant’s developing immune system12.
Not just the HMOs, but also other parts of the milk glycobiome (milk glycans) influence microbiota development and the overall health of the gut13. They protect against infectious diseases and act as prebiotics, selecting for the growth of beneficial intestinal bacteria. The prebiotic effect helps to prevent diseases such as necrotizing enterocolitis, a common and devastating disease of preterm infants. The neonatal intestinal mucosa, luminal nutrients and microbiota ensure proper homeostasis in the developing gut. So, establishing a health-promoting gut microbiome early in life is crucial13.
The amount of beneficial effects from breastfeeding depends partly on the diet of the mother14. Even though maternal nutrition has little or no effect on many of the components of her milk, her intake of unsaturated fats (especially DHA) can help her baby’s brain develop properly. That is, a baby’s brain grows fast, starting at about 350 g at birth and increasing to 925 at year one. In addition, many new connections are made between neurons in the baby’s brain. So, maternal consumption of fish and seafood like salmon and scallops that contain high levels of DHA will help her breastfed baby’s brain develop properly14. The importance of DHA and other unsaturated fats in human health was discussed in a previous issue of Wall Street International15.
Vitamin D is another important component of human breast milk16. Since parents are advised to keep their babies and infants from being exposed to very much sunlight, the only sources of vitamin D are breast milk, infant formula and dietary supplements. Human breast milk does not have enough vitamin D in it to meet the minimum daily requirements of infants. So, it’s wise to give babies and infants a daily supplement containing 400 IU of vitamin D16.
So, breastfeeding is being recognized as having a lifelong effect on both the mother and her children17. It can protect against childhood infections and malocclusion (abnormal alignment of the upper and lower teeth). It can also increase the child’s intelligence, while reducing the risk of obesity and diabetes. Breastfeeding can also lower the risk of breast and ovarian cancers as well as diabetes in the mothers. It also tends to increase the length of time that it takes a woman to become pregnant again. Recent epidemiological evidence has shown that breastfeeding does have benefits for both the mother and her children, regardless of their socio-economic status. It was estimated that “scaling up of breastfeeding to a near universal level could prevent 823 000 annual deaths in children younger than 5 years and 20 000 annual deaths from breast cancer”17.
In addition, breastfeeding is a smart investment in people and economies18. It tends to reduce infant morbidity and mortality, increase Intelligence Quotient (IQ) score, improve achievement school and increase the earnings of the parents. It also contributes to equity by giving all breastfed children a nutritional and psychological head start. So, breastfeeding can help reduce poverty and help to achieve the goals of the World Bank and Global Sustainable Development Goals to end extreme poverty and increase shared prosperity by 2030. In fact, both Bangladesh and Brazil have shown that comprehensive strategies can increase the amount of breastfeeding in society18. Similar efforts by the La Leche League (where leche is the Spanish word for milk) in 85 countries are increasing the number of women who breastfeed and the number of employers who support their breastfeeding employees in their efforts19.
However, not all babies are breastfed. They can still obtain sufficient nutrition from infant formula and vitamin supplements. They can grow up to be happy, healthy people, like I did.
1 Smith, R.E., The Myth of Natural Superfoods, in Wall Street International, Feb. 26, 2019.
2 Exclusive Breastfeeding for Six months Best for Babies Everywhere, World Health Organization, Geneva, 2011.
3 Eidelman A.I., Schanler R.J., Johnston M., Landers S., Noble L. et al., Breastfeeding and The Use of Human Milk, in Pediatrics, Volume 129, pages E827−E841, 2012.
4 Mass S., Supporting Breastfeeding in the United States: The surgeon general’s call to action, in Current Opinion Obstetrics Gynecology, Volume 23, pages 460−464 2011.
5 Lönnerdal B., Bioactive Proteins in Human Milk: Health, Nutrition, and Implications for Infant Formulas, in Journal of Pediatrics, Volume 173S, pages S4-9, 2016.
6 Andreas N.J., Kampmann B., Le-Doare K.M., Human Breast Milk: A review on its composition and bioactivity, in Early Human Development, Volume 91, pages 629-635, 2015.
7 Ballard O., Morrow A.L., Human Milk Composition: Nutrients and bioactive factors, in Pediatric Clinics of North America, Volume 60, pages 49–74, 2013.
8 Bouglé D., Bouhallab S., Dietary Bioactive Peptides: Human studies, in Critical Reviews of Food Science and Nutrition, Volume 57, pages 335-343, 2017.
9 Walker W.A., Iyengar R.S., Breast Milk, Microbiota, and Intestinal Immune Homeostasis, in Pediatric Research, Volume 77, pages 220−8, 2015.
11 Ma Z., Guan Q., Ye C., Zhang C., Foster J.A. et al., Network Analysis suggests a potentially ‘evil’ alliance of opportunistic pathogens inhibited by a cooperative network in human milk bacterial communities, in Science Reports, Volume 5, page 8275, 2015.
12 Ackerman D.L., Doster R.S., Weitkamp J.-H., Aronoff D.M., Gaddy J.A., Townsend S.D., Human Milk Oligosaccharides Exhibit Antimicrobial and Antibiofilm Properties Against Group B Streptococcus, in ACS Infectious Diseases, Volume 3, pages 595–605, 2017.
13 Pacheco A.R., Barile D., Underwood M.A., Mills D.A., The Impact of the Milk Glycobiome on the Neonate Gut Microbiota, in Annual Reviews of Animal Bioscience, Volume 3, pages 419–445, 2015.
14 Innis S.M., Impact of Maternal Diet on Human Milk Composition and Neurological Development of Infants, in American Journal of Clinical Nutrition, Volume 99 (Suppl), pages 734S–41S, 2014.
15 Smith R.E., Dietary Fat and Cancer, in Wall Street International, Dec., 2018.
16 Streym S., Højskov C.S., Møller U.K., Heickendorff L., Vestergaard P. et al., Vitamin D Content in Human Breast Milk: A 9-mo follow-up study, in American Journal of Clinical Nutrition, Volume 103, pages 107–14, 2016.
17 Victora C.G., Bahl R., Barros A.J., França G.V.A., Horton S. et al., Breastfeeding in the 21st Century: Epidemiology, mechanisms, and lifelong effect, in The Lancet, Volume 387, pages 475–490, 2016.
18 Hansen K., Breastfeeding: A smart investment in people and in economies, in The Lancet, Volume 387, page 416, 2016.
19 La Leche League International, 2019.