- Immunities & Probiotics
- Clinical & Therapeutic Uses
- Calories, Carbohydrates, Fats, Hormones & Enzymes, Natural Flavors, Proteins, Vitamins & Minerals
- Nutritional Value for Older Children
Medicine in Human Breast Milk
IMMUNITIES & PROBIOTICS
Breast milk is an ever-evolving, dynamic fluid that can be likened to ‘white blood’ as it contains live cells and bioactive compounds with incredible implications for the consumer’s immune system.
An infant’s immune system isn’t mostly developed until age two, and doesn’t reach it’s full strength until around age five. Incidentally, nature has made it biologically normal and expected for our children to continue receiving the mother’s immunities through breast milk until at least this age. In fact, immune properties actually increase during the second year of life, when a child is typically more mobile, socializing with others outside the family, and picking up a greater amount of germs.
Exclusively breastfed babies are found to have up to 300% more bifidobacterium than formula-fed babies. Our bodies house trillions of bacteria, and more than 700 types are known to exist in breast milk. By contrast, nowadays some formula companies add merely one or two strains of these bacteria to some products.
How exactly do antibodies transfer from breast milk to a baby and what are the important antibodies? Read about it here.
CLINICAL & THERAPEUTIC USES
You’ve probably heard that human breast milk can be used as a cold, fever and flu treatment, a natural birth control, a nighttime sedative, an allergy, asthma and Chron’s disease preventative, and a risk reducer for Type 2 diabetes, obesity and respiratory illness.
Still you may not know about the many other medicinal uses for breast milk. So what makes breast milk all that special?
One teaspoon of breast milk contains three million germ-killing cells (according to an Iowa Extension Service report), making every drop extremely valuable for zapping the bad guys (in fact, an ingredient called lactoferrin that’s found in concentrated doses in colostrum is used to safely kill E. Coli in the meat packing industry).
Breast milk is the only adult human tissue that contains more than one type of stem cell — in fact, three kinds of stem cells have been discovered in breast milk so far.
Donor breast milk is used clinically according to Peaceful Parenting in the prevention, treatment, or post-surgery therapy of:
- Premature babies, malabsorbtion syndromes, renal failure, inborn errors of metabolism, cardiac problems, pediatric burn cases, failure to thrive, short-gut syndrome, feeding intolerance, post-surgical, bronchi pulmonary dysplasia, treatment for infectious diseases, intractable diarrhea, gastrontentis, infantile botulism, sepsis, pneumonia, hemorrhagic conjunctivitis, omphaloele, gastroschisis, intestinal obstruction/bowel fistula, colostomy, immunodeficiency diseases, severe allergies, IGA deficiencies, and solid organ transplant, plus necrotizing enterocolitis.
Bet you can’t say all that ten times fast! Donor breast milk is even used to treat medical problems in adults, not just babies and children.
A diet of exclusive human breast milk can lower the risk of the second biggest killer of premature babies, a disease called Necrotizing Enterocolitis (NEC), by 79% percent. (Read more about NEC in the sections on premature babies and human donor milk).
In non-industrialized parts of the world, mucosal pathogens are a top killer of children under the age of five (fourteen million deaths annually, with five million dying of diarrheal disease in developing countries alone). Guess what preventative measure can be taken? Research shows that the risk of death by diarrheal disease can be reduced 14-24 times in children who are breastfed.
Nations in the industrialized world would also benefit from a majority of their children being breastfed as recommended by reducing instances of ear infections (otitis media) and infections of the acute lower respiratory tract.
Human breast milk is an effective topical treatment for many common ailments including:
- Ear and eye infections (conjunctivitis), acne, cold sores, nail fungus, chapped lips, chickenpox relief, infection prevention/treatment for small cuts, canker sores, bug bites, hives, warts, leg ulcers, diaper rash, poison ivy/oak rash, instead of saline for nasal congestion, sore throat, dry cracked nipples, and sunburn.
Perhaps most impressive is human breast milk’s capability of killing cancer cells. It contains high levels of TRAIL (TNF-related apoptosis inducing ligand), which was found in a 2012 study to have strong anticancer function. It also has a property called lactaptin that has been proven to kill cancer cells. A new drug containing this is currently in its pre-clinical trial stages with intended use as a cancer treatment.
Nutrition in Human Breast Milk
Breast milk is a one-stop nutrition shop (with a pretty good-looking window display, I might add). It’s stocked with calories, carbs, fats, hormones and enzymes, natural flavors, proteins, vitamins and minerals.
Breast milk doesn’t have a whole lot of calories, which is obviously nature’s design for human babies as rapidly packing on excess weight can be deleterious to brain-building efforts. Heavy infants are not ideal by evolutionary standards as human babies thrive best when carried constantly by their mothers.
According to study samplings, the average number of calories per 100 mL of colostrum is 58, and the average number of calories per 100 mL of mature milk is 70. Caloric value of breast milk depends mostly on fat and protein content, which itself depends on how long a mother has been producing milk, how long since the last feeding, feeding frequency, and some debated research claims that mother’s own nutritional status is a factor as well (this study disagrees, reporting that the majority of research shows breast milk caloric composition is “buffered” against influence by maternal diet and BMI).
The biggest caloric variation is between individual women rather than her particular feeding routine, ranging between about 2 g/mL – 5 g/mL according to the Institute of Medicine. If a mother produces lower-calorie milk (essentially, milk that’s lower in fat), her baby will still get all the nutrition he needs so long as she nurses frequently.
Lactose is the main type of carb in breast milk. Human milk is high in lactose compared to other species’ milk (7% in humans versus 4.8% in cow milk and 2.6% in rat milk, for example). Carbohydrates are used in part for energy, and lactose in particular helps reduce bad bacteria in the gut to increase absorption of several vital minerals and vitamins.
Did you hear that human breast milk has a high sugar content? Well, it’s true! Did you also know it has a unique type of sugars called oligosaccharides that are found nowhere else in nature?
They’re also unique to each mother as they vary by blood type. Given that these special sugars are indigestible by babies, the purpose of their existence in breast milk flummoxed experts for years until it was discovered that their purpose is to feed healthy bacteria in the gut.
Kind of like an all-you-can-eat buffet: just keep the food troughs full and diners will linger… and linger… and linger around some more (which, in the case of healthy bacteria crowds, is good for baby’s belly business).
The main energy source for babies in utero is glucose; for the first day post-birth they rely on liver glucose stores, and when they run out they get it from their diet and body fat. This is when breast milk starts making a real roly-poly cherub out of the babe.
Fats are certainly the most variable of the human milk components. This journal says breast milk fats are derived from three things: maternal diet, her adipose tissue stores, and mammary synthesis. You’d think if the mother incorporates adequate fats in her diet that her breast milk would primarily siphon it from what she consumes; however, the most recent research suggests that “a substantial proportion of the fats in milk arises from previously deposited adipose tissue (fat depots) even if caloric needs are met” (Kacew). Ah, now we kinda get how the whole breastfeeding-made-the-weight-just-fall-off thing works… (read more about how fat stores are mobilized from the mother to infant on page 99).
Compared to other species, human milk is actually low in fat (for example, about 3.8-4.2% in humans and 3.6% in cows versus 65% in hooded seals and 12.9% in dogs). However, fats comprise about 40% of total human breast milk calories, hence why the milk is also not very calorie-dense.
Humans are not meant to consume large amounts of fat or calories in one sitting; rather, they develop and thrive best with small, frequent doses. It’s all part of nature’s ingenious plan to set healthy eating patterns and self-regulation from the very start. Human infants are designed to be kept close and carried constantly, even after they begin walking, not to be left in a nest for hours before the next fat-heavy meal or only nursing them for a few days’ worth of a rich milk-binge before they’re expected to go off on their own to forage for sustenance. Human babies need constant interaction with their mother for brain growth, learning social skills, and nourishment of the body; they will undoubtedly suffer in her extended absence.
As you learned already in the previous post on foremilk and hindmilk, the amount of fat in milk purposefully changes throughout a feeding; milk from frequent feedings and ’emptied’ breasts have higher fat than milk that’s been ‘saved up’ for hours. Infrequent opportunities for a baby to be on the breasts can lead to insufficient fat intake, which in turn may result in deficiency of fat-soluble vitamins.
Human breast milk contains fats that are self-digesting. This refers to the special enzyme lipase that hitches a ride with these fats and breaks them down into tinier molecules so they can be more efficiently absorbed into the bloodstream. Human milk fats are super easy to digest (which is perfect for their less-than-perfectly-functioning intestines), making it a breeze to rely upon these fats as a constant, belly-friendly energy source. Triglycerides make up 98% of the lipids of milk. Other lipid constituents in breast milk include cholesterol, phospholipids, many minor lipids, and vitamins A, E, and D.
Another boasting point of human milk: it’s got healthy, brain-building, eye-preserving fats called linoleic and linolenic fats — not the crappy kind famous for causing clogged arteries and heartburn.
Now let’s talk about docosahexanoic acid (DHA) for a minute. DHA aids in the manufacturing of myelin sheaths, which are coverings that protect the nerves as they communicate messages to nerves elsewhere in the body. Given that DHA takes up a lot of residency in the gray matter of the brain and membranes in the eyes, I think we can all just agree to agree that’s it’s a pretty crucial component of a healthy brain. Read here about how the DHA added to infant formula is not equivalent to what naturally occurs in breast milk.
HORMONES & ENZYMES
Breast milk contains a complex slew of different enzymes, hormones and growth factors that simply cannot be replicated in man-made formula.
According to Medscape General Medicine:
“[T]he concentration of many growth factors and hormones is higher in a woman’s milk than in her plasma. The milk hormones, however, often differ in structure from their maternal serum counterparts, suggesting modification…within the mammary gland.”
Wow! Pretty cool. The uptake and activity of hormones in milk is still not very well understood, however. It’s speculated that the hormones (such as prolactin) undergo further transformation as they hit the gastrointestinal tract and again upon entering the blood stream.
Human milk is also teeming with growth factors such as Epidermal Growth Factor (EGF), Insulinlike Growth Factor-I (IGF-I), Thyroid Stimulating Hormone, prostaglandins (which help food move through digestive tract via peristalsis and protect internal lining and intestines from tissue death), and cortisol (which transports fluids and salts to the intestines). Read more about growth factors and hormones in breast milk here.
The enzymes in breast milk are incredibly stable, remaining as such in both the digestive tract after consumption and in temperature-controlled, expressed breast milk for years. In addition to the many enzymes that act as transporters for nutrients (such as iron), digestive enzymes (called amylase and digestive lipase) help pick up the slack for the newborn pancreas that’s still too immature to do it’s job efficiently on its own.
Amylase is especially important after a baby begin to consume other foods or is supplemented with formula because infants do not produce enough of their own digestive amylase until the age of two. Read more about the awesome enzymes in breast milk here.
Okay, so a flavor isn’t exactly (or at all) a nutrient, but bear with me! The flavors in breast milk do have an important role in a child’s diet. Did you know that our first tastes are actually in the womb? That’s right, amniotic fluid is known to carry the flavors of what the mother grazed upon during pregnancy.
Of course, this carries on when the baby starts breastfeeding, too. Generally, breast milk is sweet, sometimes nutty, and usually way too sugary for adult tastes. However, the flavor isn’t stagnant — nature didn’t intend for eating to be boring! Whereas formula’s flavor (uh, corn syrup?) is unchanging, breast milk’s taste is affected by its composition (high-lipase milk may taste bitter, metallic, or smell soapy, all of which are usually harmless), what the mother has eaten, and hormone fluctuations (for example, due to intense exercise, when menstruating, or if she’s pregnant).
“[W]eanling animals actively seek and prefer the flavors of the foods eaten by their mother during nursing and are more likely to accept unfamiliar flavors if they experience a variety of different flavors during the nursing period,” says Julie Mennella, known for her work in the science of “flavor memories.”
Mennella’s research has shown that these flavor profiles actually influence a child’s food preferences, too. Suffice it to say, now’s a good time to rethink the junk food and give your child a chance to associate fruits and veggies with his favorite thing — breastfeeding! Especially since most kids have such an insatiable sweet tooth. But wait — where did that come from?
“At birth, sweet liking ensures the acceptance of that which infants need to survive — the sweet taste of their mothers’ milk. Heightened preferences for sweet tastes, which persist throughout childhood and adolescence, may have an ecological basis since, in nature, sweet-tasting foods, such as fruits, are associated with energy-producing sugars, minerals, and vitamins.”
If you thought the fat content of human milk was relatively low, check this out: the protein content of human breast milk is only 1% or less! Compare that to 3.4% in cow milk, nearly 7% in giant panda milk, 7.9% in dog milk, and about 35% in cheetah milk (Parenting Science, Zoo Biology).
Why so low? Well, expedient weight gain isn’t good for baby humans (remember what I said about the expected parenting behavior of carry-care and the need for a human infant’s brain to get big, healthy and smart on nutrients before the body catches up later?), and a low amount of protein keeps growth increasing at a stable rate.
The focus on protein in breast milk is QUALITY over quantity as protein is, in fact, quite important. Amino acids make up the proteins, and one of these acids in particular, taurine, is present in breast milk in great quantities. Taurine is known to have remarkable benefits for brain and eye development. The protein immunoglobulin A (IgA) fights bacteria, respiratory viruses and intestinal parasites.
American Pregnancy Association lists even more proteins found in breast milk: lactoferrin, which “inhibits the growth of iron-dependent bacteria in the gastrointestinal tract…[and] certain organisms, such as coliforms and yeast, that require iron”; secretory IgA, which protects against “viruses and bacteria, specifically those that the baby, mom, and family are exposed to. It also helps to protect against E. Coli and possibly allergies”; lysozyme, which wards off E. Coli and Salmonella and “also promotes the growth of healthy intestinal flora and has anti-inflammatory functions”; and bifidus factor, which “supports the growth of lactobacillus. Lactobacillus is a beneficial bacteria that protects the baby against harmful bacteria by creating an acidic environment where it cannot survive.”
Contrary to cow’s milk (the basis of most formulas), the proteins in breast milk are easily absorbed. I’m sure you haven’t forgotten about Little Miss Muffett’s meal of curds and whey (wait, what is that anyway? More importantly, what the heck is a tuffet?). Well, if you were wondering, there are two classes of proteins: casein (curds) and wheys (which are more liquid-y and easier for humans to process).
According to Robert Jenness in this academic journal, human breast milk’s proteins consist of about 60-80% of whey (compared to 18% of the protein in cow milk), which is very soft and moves easily through the belly tract. Infant formula, on the other hand, is overrun with casein, which forms into tougher-to-digest curdy clots. This is in part why breastfed babies feel hungry sooner after meals than formula-fed babies — breast milk takes a quick, smooth ride from mouth to diaper rather than literally curdling up in the stomach for hours (ever seen seriously soured milk?).
VITAMINS & MINERALS
The vitamins and minerals in breast milk are highly bioavailable, meaning most of them can be both absorbed and used maximally. Breast milk has special facilitating factors that help nutrients go, as Dr. Sears says, “where they belong – in baby’s blood, not in baby’s bowels.”
Macronutrients in breast milk are largely related to the amount present in the vitamin/mineral profile of the mother. Alas, it’s recommended that she continue taking her prenatal vitamin supplement throughout lactation and consider supplementing herself first before supplementing her baby in case of suspected deficiency.
Concentrations of vitamins per liter of breast milk per the Institute of Medicine of the U.S. National Academy of Sciences (1991):
- Calcium ranging from 254 to 306 mg/L (mothers mobilize bone to provide calcium in their milk; but don’t worry, nursing mothers’ bones re-mineralize even during lactation)
- Cholesterol ranging from 100 to 150 mg/L
- Iron may range from 0.2 to 0.9 mg/L, but this depends on several factors you can learn about here
- Magnesium in concentrations of about 35 mg/L
- Phosphorous ranging from 188 to 262 mg/L
- Sodium ranging from 140 to 220 mg/L
- Vitamin C ranging from 50 to 60 mg/L so long as the mother consumes recommended daily minimum
In smaller amounts, breast milk also has zinc, molybdenum, manganese, chromium, selenium, pantothenic acid, nicotinic acid, iodine, and vitamin A and copper, plus traces of other minerals such as vitamins E, K, D and B vitamins.
“As an evolutionary development, milk composition and volume represent a compromise between the maintenance of optimal nutrient intake for the offspring and the need to minimize the nutritional drain on the lactating female. Nutrient levels in milk, therefore, are likely to meet, but not greatly exceed, the requirements of the offspring.” – pg. 97, Environmental Toxicology and Pharmacology of Human Development
NUTRITIONAL VALUE FOR OLDER CHILDREN
Has anyone ever told you that breast milk loses its nutritional value after some arbitrary age? Well, you’ll be pleased to know that science proves otherwise! (And logic, too. Think about it: does an apple lose it’s nutritional worth when your 40-year old self eats it, as opposed to your 20-year old self? The apple tree is inherently capable of producing the same perfectly nutritious fruits year after year no matter how worn it’s bark).
This study discovered that women who breastfed longer than one year made significantly fattier (more caloric) milk than those who breastfed less than six months, and milk sugar declines with duration of nursing too. As I mentioned before, it’s not all about nutrition — even some of breast milk’s most important immune properties actually increase in the second year.
In the second year (12-23 months), about 15 ounces of breast milk provides*:
- 29% of energy requirements
- 43% of protein requirements
- 36% of calcium requirements
- 75% of vitamin A requirements
- 76% of folate requirements
- 94% of vitamin B12 requirements
- 60% of vitamin C requirements (*Dewey 2001)
“Human milk expressed by mothers who have been lactating for >1 year has significantly increased fat and energy contents, compared with milk expressed by women who have been lactating for shorter periods. During prolonged lactation, the fat energy contribution of breast milk to the infant diet might be significant.” – Mandel 2005
“In a study of 250 toddlers in western Kenya, breastmilk provided, on average, 32% of the child’s total energy intake. ‘Breast milk made an important contribution to the fat and vitamin A intakes of toddlers in this community.’ – Onyango 2002
“Breast milk continues to provide substantial amounts of key nutrients well beyond the first year of life, especially protein, fat, and most vitamins.” – Dewey 2001
“Studies done in rural Bangladesh have shown that breastmilk continues to be an important source of vitamin A in the second and third year of life.” – Persson 1998