What nutrients does breast milk contain?

We all know that when a baby is born, he relies on his mother's breast milk for nutrition, because the mother's breast milk contains good nutrients that can promote the baby's growth and development. Moreover, generally speaking, babies can only drink their mother's breast milk before they are six months old, so that their stomachs can digest and absorb it. Therefore, human breast milk is something with great nutritional value. So what nutritional value does mother's breast milk have?

Breast milk is the most ideal natural food for children under 6 months old and cannot be compared with any other milk substitute. The nutritional content of breast milk also changes with changes in the mother's body after delivery and at different stages of breastfeeding. Breast milk can be divided into colostrum, transitional milk, mature milk and late milk according to different stages.

1. Protein: The protein content of breast milk is low, 1.1-1.3g/dl. It is composed of casein and lactalbumin, the former providing amino acids and inorganic phosphorus. Lactalbumin accounts for about 2/3 of the total protein. Its main components are α-lactalbumin, lactoferrin, lysozyme, and albumin. It is rich in essential amino acids, has high nutritional value, forms small clots in the stomach, and is conducive to digestion and absorption.

2. Carbohydrates: The lactose content in breast milk is 6.5-7.0g/dl, which is higher than the lactose content in cow's milk (4.5-5.0g/dl). It is the main source of heat energy for infants within 6 months after birth. Lactose promotes the brain development of infants. The beta-lactose contained in breast milk has an indirect inhibitory effect on the growth of Escherichia coli.

3. Fat: It exists in the form of an emulsion with fine particles (diameter <10μm). The content of oleic acid, which is more easily absorbed, is twice that of cow's milk, while the content of volatile short-chain fatty acids is 7 times less than that of cow's milk. It contains more long-chain unsaturated fatty acids, which are easier to digest and absorb. Breast milk contains few fat globules and a variety of digestive enzymes. Together with the lingual lipase secreted by the tongue and pharynx when the child sucks milk, it helps in the digestion of fat. Therefore, it is more beneficial for newborns and premature infants who lack pancreatic lipase.

4. Vitamins: The breast milk of normally nourished mothers contains high levels of vitamins A, E, and C, but lower levels of vitamins B1, B2, B6, B12, K, and folic acid, but can still meet physiological needs.

5. Inorganic salts: The mineral content of human milk is about 1/3 of that of cow's milk. The calcium and phosphorus content in human milk (33:15) is lower than that in cow's milk (125:99), but the calcium-phosphorus ratio is appropriate (2:1 in human milk and 1.2:1 in cow's milk), and calcium is well absorbed, so infants fed with human milk are less likely to suffer from hypocalcemia.

6. Trace elements: The iron content in both human milk and cow's milk is low, but the absorption rate of iron in human milk is significantly higher than that in cow's milk. The zinc content in human milk is lower than that in cow's milk (0.17-3.02 mg/L in human milk, 1.7-6.6 mg/L in cow's milk), but its bioavailability is high. The absorption rate of zinc in breast milk can reach 59.2%, while that in cow's milk is only 42%. Because there is a small molecular weight ligand in human milk that binds to zinc, it can promote the absorption of zinc. Because there is a small molecular weight ligand in human milk that binds to zinc, it can promote the absorption of zinc.

The absorption rate of iron in breast milk is 45%-75%, while the absorption rate of iron in cow's milk is 13%. In addition, breast milk is rich in copper, which plays a great role in protecting the baby's delicate cardiovascular system.