Breast milk

See ((Breast feeding))

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Breast milk is milk produced by mammary glands, located in the breast of a human female. 

 

Breast milk is the primary source of nutrition for newborns, containing fat, protein, carbohydrates and variable minerals and vitamins. 

 

Breast milk also contains factors that protect the infant against infection and inflammation, whilst also contributing to healthy development of the immune system and gut microbiome.

 

A baby nursing from its own mother is the most common way of obtaining breast milk.

 

Milk can be pumped and then fed by baby bottle, cup and/or spoon, supplementation drip system, or nasogastric tube. 

 

In preterm children who do not have the ability to suck during their early days of life: use of cups to feed expressed milk and other supplements is reported to result in better breastfeeding extent and duration subsequently than bottles and tubes .

Breast milk is the primary source of nutrition for newborns, containing fat, protein, carbohydrates and variable minerals and vitamins.

Mother’s milk in the NICU, predicts improve neurodevelopmental outcomes through school age in preterm infants.

It is likely nutrients or non-nutrient bioactive factors in mother’s milk that support brain development or promote recovery from perinatal brain injury to which extremely preterm infants are prone.

Breast milk can be supplied by a woman other than the baby’s mother: donated pumped milk, or when a woman nurses a child other than her own at her breast (wetnursing).

 

 

The World Health Organization recommends exclusive breastfeeding for the first six months of life.

 

 

Supplemented breastfeeding is recommended until at least age two and then for as long as the mother and child wish.

 

 

Breastfeeding health benefits to mother and child: 

 

 

Proper heat production and adipose tissue development

 

 

A 73% decreased risk of sudden infant death syndrome

 

 

Increased intelligence, 

 

 

Decreased likelihood of contracting middle ear infections, cold and flu resistance, a tiny decrease in the risk of childhood leukemia, lower risk of childhood onset diabetes, decreased risk of asthma and eczema, decreased dental problems, decreased risk of obesity later in life, and a decreased risk of developing psychological disorders, including in adopted children.

 

 

Feeding an infant breast milk is associated with lower insulin levels and higher leptin levels compared feeding an infant via powdered-formula.

 

 

Breastfeeding assists the uterus in returning to its pre-pregnancy size and reduces post-partum bleeding, through the production of  oxytocin.

 

 

Breastfeeding reduces the risk of breast cancer later in life.

 

 

Lactation may also reduce the risk for both mother and infant from both types of diabetes.

 

 

Lactation may protect the infant from specifically developing Type 2 diabetes: bioactive ingredients in breast milk could prevent excess weight gain during childhood.

 

 

Brastfeeding for at least the first 6 months of life minimizes the risk of Type 1 diabetes from occurring in the infant, inadequate breastfeeding in an infant prenatally exposed to diabetes was associated with a higher risk of the child developing diabetes later on.

 

 

There is no commercial formula that can substitute for breast milk. 

 

 

 Breast milk has appropriate amounts of carbohydrate, protein, and fat, and  milk provides vitamins, minerals, digestive enzymes, and hormones.

 

 

Breast milk contains antibodies and lymphocytes from the mother that help the baby resist infections.

 

 

The immune function of breast milk is individualized.

 

 

As mothers touch  and care for their baby, they are in contact with pathogens that colonize the baby, and she  makes the appropriate antibodies and immune cells.

 

 

At about four months of age, the internal hepatic iron supplies of the infant, are exhausted. 

 

 

Breast milk contains less iron than formula, but it’s iron is more bioavailable as lactoferrin, which carries more safety for mothers and children than ferrous sulphate supplements.

 

 

Vitamin D supplementation for breastfed infants is recommended.

 

 

Vitamin D can be synthesized by the infant via exposure to sunlight, however, many infants are deficient due being kept indoors or living in areas with insufficient sunlight. 

 

 

The hormones prolactin and oxytocin, allow women produce milk after childbirth to feed the baby. 

 

 

The initial milk produced is referred to as colostrum, which is high in the immunoglobulin IgA, which coats the gastrointestinal tract. 

 

 

Colostrum helps to protect the newborn until its own immune system is functioning properly. 

 

 

Colostrum creates a mild laxative effect, expelling meconium and helping to prevent the build-up of bilirubin.

 

 

The inability to produce enough milk postpartum is rare.

 

 

Studies indicate that mothers from malnourished regions still produce amounts of milk of similar quality to that of mothers in developed countries.

 

 

Reasons a mother may not produce enough breast milk:

 

 

Improper latch, where the baby does not connect efficiently with the nipple

 

 

Not nursing or pumping enough to meet supply, 

 

 

Medications containing hormonal contraceptives.

 

 

Illness, and dehydration. 

 

 

Postpartum hypopituitarism, which is associated with prolactin deficiency and may require hormone replacement.

 

 

The more the mother nurses her baby or pumps, the more milk is produced.

 

 

It is beneficial to nurse when the baby wants to nurse rather than on a schedule. 

 

 

A Cochrane review: a greater volume of milk is expressed with listening to relaxing audio during breastfeeding, along with warming and massaging of the breast prior to and during feeding. 

 

 

A greater volume of milk is expressed when the mother starts pumping milk sooner, even if the infant is unable to breastfeed.

 

 

Breast milk sodium concentration is higher in hand-expressed milk, when compared with the use of manual and electric pumps, and fat content is higher when the breast has been massaged, in conjunction with listening to relaxing audio. 

 

 

Composition of human breast milk:

 

 

Fat (g/100 ml) total 4.2

 

 

fatty acids – 0.6

 

 

cholesterol 0.016

 

 

Protein (g/100 ml)

 

 

total 1.1

 

 

casein 0.4

 

 

a-lactalbumin 0.3

 

 

lactoferrin (apo-lactoferrin) 0.2

 

 

IgA 0.1

 

 

IgG 0.001

 

 

lysozyme 0.05

 

 

serum albumin 0.05

 

 

β-lactoglobulin –

 

 

Carbohydrate (g/100 ml)

 

 

lactose 7

 

 

oligosaccharides 0.5

 

 

Minerals (g/100 ml)

 

 

calcium 0.03

 

 

phosphorus 0.014

 

 

sodium 0.015

 

 

potassium 0.055

 

 

chlorine 0.043

 

 

Breast milk contains complex proteins, lipids, carbohydrates and other biologically active components. 

 

 

Breast milk composition changes over a single feed as well as over the period of lactation.

 

 

((Colostrum)) is produced during the first few days after delivery.

 

 

Colostrum is a thin yellowish fluid that is the same fluid that sometimes leaks from the breasts during pregnancy. 

 

 

Colostrum is rich in protein and antibodies that provide passive immunity to the baby.

 

 

Colostrum gradually changes to become mature milk. 

 

 

In its first 3–4 days it will appear thin and watery and will taste very sweet; later it thickens as milk is thicker and creamier. 

 

 

Human milk quenches the baby’s thirst and hunger and provides the proteins, sugar, minerals, and antibodies that the baby needs.

 

 

The fat content very gradually increases, with the milk becoming fattier and fattier over time.

 

 

The level of Immunoglobulin A (IgA) in breast milk remains high from day 10 until at least 7.5 months post-partum.

 

 

Human milk contains 0.8% to 0.9% protein, 4.5% fat, 7.1% carbohydrates, and 0.2% minerals.

 

 

Carbohydrates in breast milk are mainly lactose.

 

 

Breast milk has several lactose-based oligosaccharides as minor components. 

 

 

The fat fraction contains specific triglycerides of palmitic and oleic acid and also lipids with trans bonds.

 

 

The principal proteins in breast milk are alpha-lactalbumin, lactoferrin IgA, lysozyme, and serum albumin. 

 

 

In an acidic environment of the stomach, alpha-lactalbumin binds oleic acid to form a complex called HAMLET that kills tumor cells,  contributing to the protection of breastfed babies against cancer.

 

 

Non-protein nitrogen-containing compounds, making up 25% of the milk’s nitrogen, include urea, uric acid, creatine, creatinine, amino acids, and nucleotides.

 

 

Breast milk has circadian variations in its content.

 

 

Breast milk has supplies of endocannabinoids.

 

 

Breast milk may regulate appetite in newborns.

 

 

Formula-fed babies have a higher caloric intake than breastfed babies.

 

 

Breast milk is not sterile.

 

 

Breast milk contains as many as 600 different species of various bacteria: including beneficial Bifidobacterium breve, B. adolescentis, B. longum, B. bifidum, and B. dentium, which contribute to colonization of the infant gut.

 

 

Breast milk contains a variety of somatic cells and stem cells

 

 

The somatic cells in breast milk are mainly lactocytes and myoepithelial cells derived from the mother’s mammary glands. 

 

 

The breast milk stem cells are able to differentiate into a variety of other cells involved in the production of bodily tissues.

 

 

A small proportion of milk stem cells cross over the nursing infant’s intestinal tract into the bloodstream to reach certain organs and transform into fully functional cells.

 

 

Breast milk contains a unique type of sugars: human milk oligosaccharides (HMOs), which are not present in infant formula. 

 

 

The milk oligosaccharides are not digested by the infant but help to make up the intestinal flora. 

 

 

The milk oligosaccharides act as decoy receptor that blocks the attachment of disease causing pathogens, which may help to prevent infectious diseases. 

 

 

The milk oligosaccharides alter immune cell responses, which may benefit the infant. 

 

 

There are more than a hundred different milk oligosaccharides identified

 

 

The number and composition vary between women and each milk oligosaccharide may have a distinct functionality.

 

 

The breast milk of diabetic mothers may contain elevated levels of glucose and insulin and decreased polyunsaturated fatty acids. 

 

 

Substances that can be unwittingly passed to the infant via breast milk: alcohol, viruses (HIV or HTLV-1) or medications. 

 

 

Most infants that are breastfed by their HIV positive mothers never contract the disease.

 

 

Feeding infants with breast milk of HIV-positive mothers can actually have a preventative effect against HIV transmission between the mother and child.

 

 

Most women that do not breastfeed use infant formula.

 

 

Breast milk donated by volunteers to human milk banks can be obtained by prescription.

 

 

Expressed breast milk can be stored.

 

 

Mother’s milk is noticeably thinner and sweeter than cow’s milk.

 

 

Whole cow’s milk contains insufficient iron, retinol, vitamin E, vitamin C, vitamin D, unsaturated fats or essential fatty acids for human babies.

 

 

Whole cow’s milk also contains too much protein, sodium, potassium, phosphorus and chloride:  possibly straining an infant’s immature kidneys. 

 

 

The proteins, fats and calcium in whole cow’s milk are more difficult for an infant to digest and absorb than the ones in breast milk.

 

 

Comparing milks (per cup)

 

 

Nutrient Human Milk Cow’s Milk 

 

 

Calories (Kcal) 172 146

 

 

Water (g) 215 215

 

 

Protein (g) 2.5 7.9

 

 

Fat (g) 10.8 7.9

 

 

Saturated fat (g) 4.9 4.6

 

 

Monounsaturated fat (g) 4.1 2.0

 

Polyunsaturated fat (g) 1.2 0.5

 

Omega-3 fatty acids (mg) 128 183

 

Omega-6 fatty acids (mg) 920 293

 

Cholesterol (mg) 34.4 24.4

 

 

Carbohydrate (g) 17.0 11.0

 

 

Sugars (g) 17.0 11.0

 

 

Vitamin A (IU) 522 249

 

 

Vitamin C (mg) 12.3 0

 

 

Vitamin D (IU) * 9.8 97.6

 

 

Vitamin E (mg) 0.2 0.1

 

 

Vitamin K (mcg) 0.7 0.5

 

 

Thiamin (mg) 0.0 0.1

 

 

Riboflavin (mg) 0.1 0.4

 

 

Niacin (mg) 0.4 0.3

 

 

Vitamin B6 (mg) 0.0 0.1

 

 

Folate (mcg) 12 12

 

 

Vitamin B12 (mcg) 0.1 1.1

 

 

Pantothenic acid (mg) 0.5 0.9

 

 

Choline (mg) 39.4 34.9

 

 

Calcium (mg) 79   276  

 

 

Iron (mg) 0.07 0.07

 

 

Magnesium (mg) 7.4 24.4

 

 

Phosphorus (mg) 34.4 222

 

 

Potassium (mg) 125 34

 

 

Sodium (mg) 42 98 122

 

 

Zinc (mg) 0.4 1.0 0.7

 

 

Copper (mg) 0.1 0.0

 

 

Manganese (mg) 0.1 0.0

 

 

Selenium (mcg) 4.4 9.0

 

 

Milk is generally fortified with vitamin D in the U.S.

 

 

Almost all medicines pass into breastmilk in small amounts by a concentration gradient.

 

 

Whether a medication passes into breastmilk depends on the amount of drug bound by maternal plasma proteins, the size of its molecule, its pH. and the lipophilicity of the drug.

 

 

Non-protein bound, low molecular weight, or highly lipid-soluble drugs are more likely to enter the breast milk in larger quantities.

 

 

Generally medications are safe that the mother can use while breastfeeding.

 

 

Medications that may be toxic to the baby while breastfeeding and thus should not be used in breastfeeding mothers: 

 

 

Amiodarone

 

 

Anticancer drugs

 

 

Bromocriptine

 

 

Cyclosporine 

 

 

Lithium

 

 

Methotrexate 

 

 

Drugs of abuse, such as cocaine, amphetamines, heroin, and marijuana cause adverse effects on the infant during breastfeeding. 

 

 

Hormonal products and combined oral contraceptives should be avoided during the early postpartum period as they can interfere with lactation.

 

 

Medications that may stimulate the production of breast;Domperidone.

 

 

Consuming alcohol after the birth of the infant is considered safe.

 

 

High caffeine intake by a breastfeeding mother may cause their infants to become irritable or have trouble sleeping.

 

 

A meta-analysis has shown that breastfeeding mothers who smoke expose their infants to nicotine, which may cause respiratory illnesses, including otitis media in the nursing infant.

It has been established that trans fats in human breast milk fluctuate with maternal consumption of trans fat,.

Pesticides and other toxic substances bioaccumulate in breast milk.

 

 

A commercial market for human breast milk exists, both in the form of a wet nurse service and as a milk product.

 

 

Breast milk is exchanged by human milk banks.

 

 

Breast milk is considered to be healthier than cow’s milk and infant formula in the first 6 months of life.

 

 

Feeding an infant breast milk from a healthy wet nurse rather than that of its biological mother is rarely preferred.

 

 

Milk purchased online may be improperly sanitized or stored, and may contain food-borne illness and infectious diseases such as hepatitis and HIV.