Breast milk: composition and functions

Mainly, breast milk contains 88% water, the quantity the baby needs during the first months, which may explain why babies who are breastfed do not need to drink additional water, even in hot weather. We must not give the baby water or other drinks before six months, as this could trigger diarrhea, infections and other diseases.

Protein: are 0.9% of breast milk, which contains casein, whey proteins, mucins and non-protein nitrogen. These occur in the mammary gland, except for serum albumin, which comes from the maternal circulation. It contains between 30% and 40% casein and 60% whey.

Casein: brings the newborn a dose of amino acids and minerals like calcium and phosphorus. The casein in milk is very digestible; the clots it forms are mild in comparison with thick clots that cow's milk forms.

Lactoferrin: another protein that promotes iron absorption in the intestine and inhibits the growth of pathogenic bacteria in the gastrointestinal tract while taking iron that bacteria need to multiply. Cow's milk has virtually no lactoferrin.

Lysozyme: is the most abundant enzyme in breast milk, and its primary role the development and maintenance of the infant's intestinal flora. This enzyme contains anti-inflammatory properties, is present in 40% in milk and its content is 300 times that of cow's milk.

Lipase: activates the gastrointestinal tract which aids digestion, producing free fatty acids and glycerol. Babies fed with breast milk have a high and highly efficient fat absorption. It also produces a protective effect against bacteria, viruses and protozoa in the antimicrobial action of the enzyme.

Antibodies: breast milk is extremely rich in antibodies, mainly in colostrum, it is rich in Ig A antibodies, which bind to the virus and prevent bacteria from penetrating the intestinal mucosa, in addition to inhibit the colonization of these pathogens in baby's intestine.

Taurine and carnitine: essential for the development and maturation of the central nervous system, retina and good development of the baby. Taurine also aids in the absorption of lipids, osmo-regulation and calcium transport; it is crucial to the formation of bile salts that are essential for digestion. Carnitine is involved in the synthesis of brain lipids.

Carbohydrates: Lactose is the carbohydrate most present in breast milk, providing 40% of calories from breast milk, and is essential for the absorption of calcium, iron, magnesium, etc. Other carbohydrates such as neutral oligosaccharides, glycoproteins, glycosphingolipids, amino-sugars and acetyl are present too.

Minerals: All minerals that a newborn needs are in breast milk, with a very high absorption capacity. The composition of minerals like sodium, potassium and chloride promote baby's kidney function by favoring the metabolic capacity of the newborn.

Calcium and phosphorus: the percentages of calcium and phosphorus in human milk are 2:1, are minerals that are easily absorbed. In cow's milk, phosphorus dominates the match (1:3), which may trigger hypocalcemia in the newborn.

Iron: very easily absorbed when it comes from milk. There are studies that show that iron absorption decreases with the early introduction of solid foods before 6 months of age, then avoid solid foods, in this way anemia and other complications are avoided.

Vitamins: although they cover all the needs of the baby, breast milk vitamin percentages vary depending on the quality of mother's milk due to their nutritional status.
The main vitamins it contains are: A, K, E, D, vitamin B12 (cobalamin), B6 (pyridoxine), B1 (thiamin), folic acid (B9), B3 (niacin) and pantothenic acid (B5). It is recommended for vegetarian mothers to take a B12 supplement as a vegetarian diet does not contain the same sources.

It is also rich in folic acid to synthesize essential amino acids, DNA, RNA and hemoglobin and vitamin C.