Breast milk

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Two 25ml samples of human breast milk. The left hand sample is foremilk, the watery milk coming from a full breast. The right hand sample is hindmilk, the creamy milk coming from a nearly empty breast.^[1]

Human Breast milk refers to the milk produced by a mother to feed her baby. It provides the primary source of nutrition for newborns before they are able to eat and digest other foods; older infants and toddlers may continue to be breastfed. The baby nursing from its own mother is the most ordinary way of obtaining breastmilk, but the milk can be pumped and then fed by baby bottle, cup and/or spoon, supplementation drip system, and nasogastric tube. Breastmilk can be supplied by a woman other than the baby's mother; either via donated pumped milk (for example from a milk bank), or when a woman nurses a child other than her own at her breast - this is known as wetnursing.

The World Health Organization recommends exclusive breastfeeding until six months of age,^[2] with solids gradually being introduced around this age when signs of readiness are shown. Breastfeeding is recommended for at least two years and should continue as long as mother and child wish.^[2] Breastfeeding continues to offer health benefits into and after toddlerhood.^[3] These benefits include; lowered risk of Sudden Infant Death Syndrome (SIDS),^[4] increased intelligence, decreased likelihood of contracting middle ear infections, cold, and flu bugs, decreased risk of some cancers such as childhood leukemia, lower risk of childhood onset diabetes, decreased risk of asthma and eczema, decreased dental problems, and decreased risk of obesity later in life, decreased risk of developing psychological disorders .^[5][6]

Breastfeeding also provides health benefits for the mother. It assist the uterus to return to its pre-pregnancy size and reduces post-partum bleeding as well as assisting the mother to return to her pre-pregnancy weight. Breastfeeding also reduces the risk of breast cancer later in life.^[7]

[edit] Production

Under the influence of the hormones prolactin and oxytocin, women produce milk after childbirth to feed the baby. The initial milk produced is often referred to as colostrum, which is high in the immunoglobulin IgA, which coats the gastrointestinal tract. This helps to protect the newborn until its own immune system is functioning properly, and creates a mild laxative effect, expelling meconium and helping to prevent the build up of bilirubin (a contributory factor in jaundice).

There are many reasons a mother may not produce enough breast milk. Some of the most common are an improper latch (i.e. the baby does not connect efficiently with the nipple), not nursing or pumping enough to meet supply, certain medications (including the contraceptive pill), illness, and dehydration. A rarer reason is Sheehan's syndrome, also known as postpartum hypopituitarism, which is associated with prolactin deficiency; this syndrome may require hormone replacement. Malnourishment of the mother is a significant problem for women in developing countries, as malnourished women are often unable to produce breast-milk.

The amount of supply depend on how often the mother nursing and/or pumping; the more the mother nurses her baby, or pumps, the more milk is produced.^{[8][9][10][11][12]} It is very helpful to nurse on demand - to nurse when the baby wants to nurse rather than on a schedule. If pumping, it is helpful to have an electric high grade pump so that all of the milk ducts are stimulated. Some mothers try to increase their milk supply in other ways - by taking the herb fenugreek, used for hundreds of years to increase supply^[13] ("Mother's Milk" teas contain fenugreek as well as other supply-increasing herbs); there are also prescription medications that can be used, such as Domperidone (off-label use) and Reglan.^{[citation needed]} Increasers of milk supply are known as galactagogues.

[edit] Composition

The exact integrated properties of breast milk are not entirely understood^{[citation needed]}, but the nutrient content after this period^{[citation needed]} is relatively consistent and draws its ingredients from the mother's food supply. If that supply is found lacking, content is obtained from the mother's bodily stores. The exact composition of breast milk varies from day to day, depending on food consumption and environment, meaning that the ratio of water to fat fluctuates. Foremilk, the milk released at the beginning of a feed, is watery, low in fat and high in carbohydrates relative to the creamier hindmilk which is released as the feed progresses. The breast can never be truly "emptied" since milk production is a continuous biological process.

Human milk contains 0.8% to 0.9% protein, 10% to 15% fat, 6.9% to 7.2% carbohydrates and 0.2% ash (minerals). Carbohydrates are mainly lactose; several lactose-based oligosaccharides have been identified as minor components. The fat fraction contains specific triglycerides op Palmitic and Oleic acid (O-P-O triglycerides) and also quite a large quantity of lipids with trans bonds (see: trans fat) that are considered to have a health benefit. They are vaccenic acid, and Conjugated linoleic acid (CLA) accounting for up to 6% of the human milk fat ^{[15] [16]}. The principal proteins are casein homologous to bovine beta-casein, alpha-lactalbumin, lactoferrin, IgA, lysozyme and serum albumin. Non-protein nitrogen-containing compounds, making up 25% of the milk's nitrogen, include urea, uric acid, creatine, creatinine, amino acids and nucleotides.^[17][18] Breast milk has circadian variations; some of the nucleotides have acrophases during the night, others during the day.^[19]

Mother's milk has been shown to supply a type of endocannabinoid (the natural neurotransmitters which marijuana simulates), 2-Arachidonoyl glycerol.^[20]

Though it now is almost universally prescribed, in some countries in the 1950s the practice of breastfeeding went through a period where it was out of vogue and the use of infant formula was considered superior to breast milk. However, it is now universally recognized that there is no commercial formula that can equal breast milk. In addition to the appropriate amounts of carbohydrate, protein and fat, breast milk also provides vitamins, minerals, digestive enzymes and hormones - all of the things that a growing infant will require. Breast milk also contains antibodies and lymphocytes from the mother that help the baby resist infections. The immune function of breastmilk is individualized, as the mother, through her touching and taking care of the baby, comes into contact with pathogens that colonize the baby and consequently her body makes the appropriate antibodies and immune cells.

Women who are breastfeeding should consult with their physician regarding substances that can be unwittingly passed to the infant via breast milk, such as alcohol, viruses (HIV or HTLV-1) or medications.

Most women who do not breastfeed use infant formula, but breast milk donated by volunteers to human milk banks can be obtained by prescription in some countries.^[21]

[edit] Storage of expressed breast milk

Breast milk storage containers.

Expressed breast milk can be stored for later use. It is recommended that the milk is stored in hard-sided containers with airtight seals. Plastic bags specifically manufactured for the storage of expressed breast milk can be used for designed for storage periods of less than 72 hours. The amount of time that it can be safely stored for use by health infants in a home-based situation is given in this table^[22].

[edit] Comparison to other milks

All mammal species produce milk, but the composition of milk for each species varies widely and other kinds of milk are often very different from human breast milk. As a rule, the milk of mammals that nurse frequently (including human babies) is less rich, or more watery, than the milk of mammals whose young nurse less often. Human milk is noticeably thinner and sweeter than cow's milk. Left in a cup, the cream will rise and form a thin layer.

Whole cow's milk does not contain sufficient vitamin E, iron, or essential fatty acids, which can make infants fed on cow's milk anemic. Whole cow's milk also contains excessive amounts of protein, sodium, and potassium which may put a strain on an infant's immature kidneys. In addition, the proteins and fats in whole cow's milk are more difficult for an infant to digest and absorb than the ones in breast milk.^[23] Evaporated milk may be easier to digest due to the processing of the protein but is still nutritionally inadequate. A significant minority of infants are allergic to one or more of the constituents of cow's milk, most often the cow's milk protein.^[24] These problems can also affect infant formulas derived from cow's milk.

[edit] Alternative uses for breast milk

In addition to providing essential nourishment to infants, human milk; i.e., breast milk, has a number of valuable uses, especially medicinal uses, for both children and adults. It has been used medicinally for thousands of years^[25]. The antibacterial and healing properties of breast milk are often overlooked, even by the nursing mothers themselves^[26]. Breast milk, if properly expressed and stored, is a sterile solution and can be used in a variety of ways to promote healing and clean wounds^[27]. Breast milk contains strong antibodies and antitoxins that many people believe promote healing and better overall health.

Breast milk has been used as a home remedy for minor ailments, such as conjunctivitis, insect bites and stings, contact dermatitis, and infected wounds, burns, and abrasions. Breast milk has also been used alternatively to boost the immune system of ill persons having viral gastroenteritis, influenza, the common cold, pneumonia, etc., because of its immunologic properties. However, breast milk should never be seen or construed as a "cure all". Some medical experts are convinced that breast milk can induce apoptosis in some types of cancer cells, however, more research and evidence are needed in this area of cancer treatment^[28].

A minority of people, including restaurateur Hans Lochen of Switzerland, have used human breast milk, or at least advocated its use, as a substitute for cow's milk in dairy products and food recipes^[29]. Tammy Frissell-Deppe, a family counselor specialized in attachment parenting, published a book, titled A Breastfeeding Mother's Secret Recipes, providing a lengthy compilation of detailed food and beverage recipes containing human breast milk^[30]. The animal rights organization known as PETA ignited a firestorm of criticism when it urged a dairy company to replace the cow's milk they use in their ice cream products with human breast milk as a way to stop cattle abuse^[31][32]. Human breast milk is not produced or distributed industrially or commercially, because the use of human breast milk as a dairy food or recipe ingredient is extremely bizarre and counterintuitive to the vast majority of cultures around the world, and most disapprove of such a practice, as it has never been widely accepted historically^[33]. This lack of acceptance is primarily due to strong social ethics and religious morality that command deep respect for human life and the human body and also command a special moral treatment of human body fluids^[34].

Attempts to formulate soap from breast milk have also been made, and those who use it claim that its effectiveness as a cleanser is greater than, or equal to, that of traditional soaps^[35].

[edit] Passing of unwanted substances

Despite the risk of substances transmitting from the mother to the child through breast milk, breastfeeding has far more advantages than e.g. infant formulas, and, with few exceptions, the WHO recommends exclusive breastfeeding for the first 6 months of life.^[36]

The milk producing cells are most permeable to drugs during the first postpartum week. ^[37]

Drug characteristics that increase excretion in milk include:^[37]

1. Not plasma protein binding
2. Non-ionized
3. Low molecular weight
4. Lipid solubility rather than water solubility
5. Weakly alkaline rather than weak acid

Drugs are transferred from blood plasma across ductal cells to the milk by diffusion or active transport. The latter may result in higher concentration of the drug in the breast milk than in the plasma of the mother.^[37]

The amounts of most drugs in milk do not exceed 2% of the total ingested dose.^[37]

[edit] Medications

Medications considered safe regarding content in milk are:

• Aspirin^[38]
• Acetaminophen^[38]
• Most antibiotics^[38]
• Antihistamines^[38] (allergy and cold preparations)

Still, consultation with a health care provider is reasonable for a breastfeeding woman before taking any medications.^[38]

Medication requiring some caution are:

• Laxatives^[38]
• Asthma medications containing theophylline^[38]
• Sedatives (e.g., Valium and phenobarbital)^[38]

Alcohol and caffeine are safe if taken in small amounts.^[38] Nicotine, on the other hand, passes to the child through breast milk and may cause serious medical problems.^[38]

Medications that are harmful to the breast-fed infant, and should be avoided if possible, are:

• Atropine^[38]
• Drugs for hyperthyroidism^[38]
• Cancer chemotherapy^[38]
• Tetracyclines^[38]
• Chloramphenicol^[38]
• Iodides^[38]
• Reserpine^[38]
• Narcotics^[38]
• Lithium^[38]
• Radioactive preparations^[38]
• Ergot preparations ^[38]

If they can not be avoided or substituted for medical reasons, breast-feeding should be temporarily discontinued.^[38]

Prolonged use of the following medications should only be done under direct supervision of a physician:

• Steroids^[38]
• Oral contraceptives^[38]
• Sedatives^[38]
• Diuretics^[38]
• Anticonvulsants^[38]

[edit] Environmental pollutants

Environmental pollutants found in breast milk are usually not harmful, and should only be considered when environmental levels are unusually high. In addition, there has been a decrease in environmental levels, also resulting in a decrease breast-milk levels. Pollutants that are of most concern are pesticides, organic mercury and lead. DDT and dieldrin are unavoidable, and can also be detected infant formulas.^[38]

[edit] See also

• Lactation
• Lactation room
• Male lactation
• Breast pump
• Human milk banking in North America
• Infant formula
• Donor Expressed Breast Milk

[edit] References

[edit] External links

• The Case against breastfeeding
• Comparison of Human Milk and Formula
• United Nations University Centre - Constituents of human milk - including comparison of human and cow's milk ones
• La Leche League Human Milk Storage Information
• Children's Health Topics: Breastfeeding
• Infant nutrition information from Seattle's Children's Hospital and Regional Medical Center
• Moms pay big for other mothers' milk, Janine DeFao, San Francisco Chronicle, 9 April 2006. An article about the market on human milk.