Human Breast Milk Is Designed for Both Mother and Baby
The advantages of breast milk are piling up:
alternatives are not near as healthy or protective
by Jerry Bergman, PhD
New research on the importance of breast milk to nourish infants has continued to provide evidence of its superiority over other means of infant feeding. All mammals, including monotreme, marsupial, and eutherian, feed their young with milk secreted in the female mammary glands. The word ‘mammary’ is the source for the word mammal. Yet, as one journal noted: “Human milk is essential, yet scientists know little about it.”[1] This ignorance is slowly being reduced. We now know that human breast milk is far more complex than once believed even a few years ago. The more it is researched, the more complex and important it becomes. This makes it seem tragic that only one in four infants are exclusively breastfed until they are six months old.
One analysis determined that breastfeeding reduced first-year post-perinatal infant mortality by a whopping 33 percent.[2] This reduction in infant mortality is yet another benefit added on to the other breast-milk blessings as I documented in my previous post on breast milk.[3] This finding would be expected from the creation worldview, which teaches that breast milk was specifically designed to maximize the benefits of breastfeeding and, concurrently, aid in the health of the child and mother as well. These findings would not be expected by the evolutionary story that milk evolved from the sweat that the infant licked from the mother’s body. Specifically, evolutionists teach that the evolutionary origin of milk was
a glandular skin secretion in synapsids (the lineage ancestral to mammals), perhaps as early as the Pennsylvanian period, that is, approximately 310 million years ago (mya). Early synapsids laid eggs with parchment-like shells intolerant of desiccation and apparently dependent on glandular skin secretions for moisture. Mammary glands probably evolved from apocrine-like glands that combined multiple modes of secretion and developed in association with hair follicles.[4]
Obviously, a mother’s sweat would not provide the required nutrients to allow the infant to survive. Oftedal adds that
the evolutionary origin of milk constituents supports a scenario in which these secretions evolved into a nutrient-rich milk long before mammals arose. A variety of antimicrobial and secretory constituents were co-opted into novel roles related to nutrition of the young. Secretory calcium-binding phosphoproteins may originally have had a role in calcium delivery to eggs; however, by evolving into large, complex casein micelles, they took on an important role in transport of amino acids, calcium and phosphorus… All primary milk constituents evolved before the appearance of mammals, and some constituents may have origins that predate the split of the synapsids from sauropsids (the lineage leading to ‘reptiles’ and birds).[5]
Note that several of the attempts to explain the evolution of milk were admittedly speculative as indicated by the added italics in the quote above.
Importance for the Immune System
It has long been known that Immunoglobulin A (IgA) is secreted into breast milk to help establish the child’s immune defenses. In healthy children and adults, IgA is the most abundant antibody type (about 70 percent of total body Immunoglobulin). It protects the mucosal tissues, including those that secrete tears, saliva, sweat, and secretions from the genitourinary tract that result from microbial infection. IgA also maintains microbiota immune homeostasis. Furthermore, new research revealed that the mother passes a unique set of breast milk antibodies to her child to meet the child’s needs.[6] This maintenance is critical, not only for protecting the baby against enteric pathogens (meaning those occurring in the intestines), but also in helping to develop the infant’s intestinal microbiota which is critical for the babies health.
Importance for Brain Development
By analyzing human milk samples across global populations, researchers identified a carbocyclic sugar called myo-inositol which promotes brain development. The formation and maintenance of brain connectivity also results from the influences of genetics, experience, and the environment. Brain development is particularly important during two stages of life, when the brain is growing during infancy and when synapses loss occurs during aging. Specifically, the researchers documented that myo-inositol produces
substantial benefits of the human milk component myo-inositol for developing synapses across species, including in human neurons. These findings demonstrate that myo-inositol promotes neuronal connectivity and can guide dietary recommendations across life stages. This can be significant for pediatric nutrition and the improvement of infant formulas in under resourced areas with conditions that prevent sufficient breastfeeding.[7]
Breast Feeding Lowers the Mother’s Risk of Breast & Ovarian Cancer and Type 2 Diabetes
Breastfeeding not only helps the baby, but also lowers the mother’s risk of breast and ovarian cancer. New research determined that it also lowers her risk of developing type 2 diabetes.[8] Breastfeeding researchers detected changes in metabolism that resulted from an improvement in insulin sensitivity and an increase in the numbers of insulin-producing, pancreatic beta-cells compared to mice that did not lactate.
Although this research was on mice, the next step is to apply this finding to humans to determine the cause of the protection against type 2 diabetes that breastfeeding provides. One trigger for the development of diabetes is the loss of beta-cells’ effectiveness to produce enough insulin to effectively lower blood sugar. Insulin lowers blood sugar by moving it from the blood and into the cell where it is required for the cell’s energy requirements. Genetic mutations and obesity often cause insulin resistance, which becomes worse during pregnancy, especially in the third trimester. Although many people assume that nursing protects against diabetes by causing weight loss, this new research suggests that the protective effects of breastfeeding likely occurred by multiple mechanisms that are independent of weight loss.
Researchers at the Icahn School of Medicine recently discovered a family of hormones secreted by the breast duct cells called “mammokines.” These mammokines contribute to normal mammary biology as well as fat cell physiology and energy balance control.[i] The findings have important implications for causing and treating both breast cancer and lactation-related disorders. Mammokines also influence the newborn’s health, such as metabolic syndromes that are linked to mammary adipose (fat tissue) dysfunction.[ii]
This research may help clinicians understand the cause and treatment of certain kinds of cerebral palsy.[iii] Cerebral palsy (a palsy is a condition that affects body movement) is an untreatable disease which ranges from mild to severe. About 60,000 babies are born premature (before 32 weeks’ gestation) in the United States each year. Ten percent of these babies will develop cerebral palsy from damage to the nerve fibers in the brain’s white matter, causing cerebral palsy. In experiments using neonatal mice, Duke University researchers have identified a molecule in breast milk that triggers the process, causing the brain stem cells to produce cells that create new white matter, reversing the conditions causing cerebral palsy.[iv] Not breast feeding may contribute to causing brain damage.
Can Males Chest Feed Infants?
The recent claim that transgender women (who are biological males) can “chest feed” if given female hormones is irresponsible for several reasons. These reasons include the effects of male hormone secretions and supplements on the health of both the baby and the male are unknown. Male secretions cannot replace the many benefits of breast milk which are discussed above. Men cannot normally lactate or breastfeed. While people born male have the anatomy required for lactation (nipples, mammary and pituitary glands), they lack the hormone levels required to produce breast milk. Use of large doses of female hormones can cause some males to lactate. Because no long-term studies exist to determine the effects of milk produced in males; consequently, this is a reckless experiment. Men who produce their own milk through the use of hormone drugs also create problems for the infant, such as these drugs can pass into breast milk in large enough amounts that can cause babies to have an irregular heartbeat.
Summary
As is true in other areas of biology, ongoing research has determined that human anatomy and physiology is far more complex than once believed. This is also true of breast milk. The benefits to the mother and child are so great that to not breastfeed at least for, ideally, six months or as long as possible, should be looked at with concern. Low rates of breastfeeding in the United States alone add over three billion dollars annually to the medical costs for the mother and child. The creation worldview explains the origin of the infant feeding system, and, in contrast, the Darwinian worldview does not.
Update 13 Sept 2023: Certain proteins found in breast milk are essential for baby’s healthy gut (Medical Xpress).
References
[1] Purtill, Corinne. Human milk is essential, yet scientists know little about it. UCSD plans to change that. Los Angeles Times; https://medicalxpress.com/news/2023-03-human-essential-scientists.html, 30 March 2023.
[2] Arbor, Ann. Breastfeeding associated with a 33% reduction in first-year post-perinatal infant mortality. Elsevier; https://www.elsevier.com/about/press-releases/research-and-journals/breastfeeding-is-associated-with-a-33-reduction-in-first-year-post-perinatal-infant-mortality, 24 July 2023.
[3] Bergman, Jerry. Human breast milk is best for infants. Cow milk is for cows: Human breast milk is designed for humans. New research provides yet another reason why human breast milk is the best for human infants; https://crev.info/2020/09/human-breast-milk-best/, 27 September 2020.
[4] Oftedal, O.T. The evolution of milk secretion and its ancient origins. Animal 6(3):355-68;
https://pubmed.ncbi.nlm.nih.gov/22436214; doi: 10.1017/S1751731111001935, March 2012. /
[5] Oftedal, 2012; italics added.
[6] Johnson-Henc, Chelseá B. Stability and heterogeneity in the anti-microbiota reactivity of human milk-derived immunoglobulin A. Journal of Experimental Medicine 220(8):e20220839, 20 March 2023.
[7] Paquette, Andrew F., et al. The human milk component myo-inositol promotes neuronal connectivity. PNAS 120(30) e2221413120; https://www.pnas.org/doi/full/10.1073/pnas.2221413120, 11 July 2023.
[8] Crawford, Serena. How breastfeeding lowers mothers’ risk of developing type 2 diabetes. Yale School of Medicine; https://medicine.yale.edu/intmed/news-article/how-breastfeeding-lowers-the-risk-of-developing-type-2-diabetes/, 18 July 2023.
[i] Patel, Sanil et al.. Mammary duct luminal epithelium controls adipocyte thermogenic programme. Nature. 620: 192–199. 26 July 2023.
[ii] Mt Sinai Hospital. Mammary Glands Control Overall Energy Balance and Fat Metabolism. Mt Sinai Hospital, 26 July 2023.
https://www.mountsinai.org/about/newsroom/2023/mount-sinai-researchers-uncover-how-mammary-glands-control-overall-energy-balance-and-fat-metabolism
[iii] Popez, Stephanie. Newly Identified Lipid in Breast Milk Might Reduce Cerebral Palsy in Infants Duke University Health Report. Aug 3, 2023.
https://corporate.dukehealth.org/news/newly-identified-lipid-breast-milk-might-reduce-cerebral-palsy-infants.
[iv] Chao, Agnes. et al., 20-αHydroxycholesterol, an oxysterol in human breast milk, reverses mouse neonatal white matter injury through Gli-dependent oligodendrogenesis. Stem Cell. 30(8):1054-1071. 3 August 2023. https://www.cell.com/cell-stem-cell/fulltext/S1934-5909(23)00255-2.
Dr. Jerry Bergman has taught biology, genetics, chemistry, biochemistry, anthropology, geology, and microbiology for over 40 years at several colleges and universities including Bowling Green State University, Medical College of Ohio where he was a research associate in experimental pathology, and The University of Toledo. He is a graduate of the Medical College of Ohio, Wayne State University in Detroit, the University of Toledo, and Bowling Green State University. He has over 1,300 publications in 12 languages and 40 books and monographs. His books and textbooks that include chapters that he authored are in over 1,800 college libraries in 27 countries. So far over 80,000 copies of the 60 books and monographs that he has authored or co-authored are in print. For more articles by Dr Bergman, see his Author Profile.