Colostrum

What is Colostrum

The secretion of the breast, which in women normally begins after childbirth (only exceptionally before), passes through three phases. As a result, the balance of nutrients in breast milk also changes during these three stages of breastfeeding:

1. in the first 5 days the colostrum is produced
2. transitional milk from the 5th-6th to the 10th day
3. from the 10th to the 20th day (onwards) mature milk.

Colostrum, once mistakenly called " witch's milk " or " dead milk ", was considered harmful to the suckling child for centuries; the doctors claimed that they should avoid and suggest alternative practices that lasted for at least the first 7 days.

In reality, colostrum is a fundamental element for the first development, as it boasts the unparalleled characteristics of favoring the immune defenses of the child and allowing its optimal development of the intestine.

Functions and Nutrients

The newborns have still immature digestive systems, with a different capacity to digest and absorb the nutrients of the diet compared to the adult; for this reason, the colostrum is quite dense and, compared to mature milk, contains a smaller aqueous fraction to concentrate more elements in solution and in suspension. Not surprisingly, colostrum appears as a yellowish (not whitish) and viscose (non-liquid) secretion.

Laxative effect

Colostrum has a very slight laxative effect on the child (probably the reason for its bad reputation in past years); this circumstance, apparently negative, is instead very important to favor the very first passage of feces (called meconium or meconium ) inside the "virgin" intestine.

In this way, the colic portion can develop what will be its definitive intestinal bacterial flora (present on the mother's breast and selected thanks to the food's immune potential).

It's not all; this mild laxative effect has the function of promoting the excretion of bilirubin from the body of the child who, as we shall see, tends to retain it in excess tending to jaundice. This surplus of bilirubin is due to the death of a large number of red blood cells (erythrocytes) respectively produced in response to the total volume reduction caused by the detachment with the mother at the time of birth.

Immune function and growth factors

Colostrum contains a large amount of white blood cells (lymphocytes) and immunoglobulins, especially type A, but also IgG and IgM. These defensive proteins are endowed with a remarkable anti-infective ability and act above all in the intestine; they represent the main components of the so-called "adaptive immune system". It is also hypothesized that IgA, or the most numerous, can be absorbed in the intestine and, once in circulation, secreted again in different districts.

Other colostrum factors belong to the "innate immune system" and are: lactoferrin, lysozyme, lactoperoxidase, complement and proline-rich polypeptides (PRP).

Colostrum also provides a fair number of cytokines (messenger peptides capable of modifying the behavior of certain cells), including: interleukins, tumor necrosis factors, chemokines, etc.

There is no shortage of growth factors, such as the insulin-like I (IGF-1) and II (IGF-2), transformation factors alpha, beta 1 and beta 2, fibroblast growth factors, epidemic growth factor, stimulating factors the growth of granulocytes and macrophages, platelet-derived growth factor, vascular endothelial growth factor and colony stimulating factor 1.

In summary, antimicrobials and growth factors represent the main BIOactive component of colostrum; while the former select the intestinal bacterial flora and protect the mucosa from pathogens, the latter promote the development of the intestine itself. We also remember in the breast milk there are some oligosaccharides able to act as prebiotic agents on the intestinal bacterial flora.

Proteins and Fats

Colostrum is also rich in proteins and, among these, albumins are not lacking; these are extremely useful peptides in the transport of numerous substances (such as drugs, hormones, etc.), mineral salts and white blood cells (leukocytes). Among the vitamins, retinol equivalents (vit. A) stand out and, with regard to mineral salts, the most present is sodium chloride (it would be interesting to understand whether this depends on the nutrition of the nurse or not).

In transitional milk, compared to colostrum, the percentage of fat and lactose increases (therefore the caloric intake) and the proportion of proteins and minerals decreases. As the months pass, breast milk continues to maintain its nutritional properties, while the quantity tends to decrease physiologically; after 6 months, a woman produces on average 500cc a day, which is an insufficient amount to cover the nutritional needs of a child of that age. Therefore, it is possible to continue to give milk even after 6 months, provided that it is an integrating product of food for weaning.

Colostrum has therefore characteristics almost opposite to those of mature milk, because the latter is rich in lactose, lipids and potassium, but is poor in proteins (0.9%, against 2.8% of colostrum).

Curiosity

The importance of colostrum has long been known also in veterinary medicine: in animal breeding, calves are fed with artificial milk (for the lowest cost), except for the first 7 days, when colostrum is used because it is rich in defensive substances.