What is transitional milk?
A newborn changes literally every day, and the same can be said about breast milk. With the advent of milk, the breast can increase to an impressive size, and changes occur not only outside but also inside. During the first week, the milk-producing cells and the connections between them are rearranged and prepare the breast for the upcoming feeding. From that moment until about the end of the second week they will produce the so-called transitional milk.
“After the placenta is released, the level of progesterone, the hormone of pregnancy, begins to decline rapidly,” explains Professor Peter Hartmann of the University of Western Australia, a leading specialist in the study of the composition of breast milk. “As the level of progesterone decreases, milk synthesis increases and its composition approaches normal, although it takes another couple weeks to fully ripen the milk. ”
Stages of breast milk production: intermediate phase
If colostrum is the very first food of the baby, and mature milk is its main food for a long time, then transitional milk is a kind of bridge between them.
They should be considered as three different stages of milk production, and not three types of milk. The main components remain unchanged throughout breastfeeding, only their number changes, depending on the circumstances. During the transition period, the composition of milk undergoes the most significant changes, and this happens every day in accordance with the changing needs of the child.
Milk changes because it contains bioactive components, including cells, hormones and beneficial bacteria. The transition to mature milk does not occur simultaneously: the composition changes gradually and in exact accordance with the developmental needs of the baby.
“The main influence on the composition of milk is exerted by the volume of its production by the mother,” says Professor Hartman. “The composition of milk differs at a lower and higher level of production.”
Transitional milk: an increase in quantity
As the child grows, he needs more food and a different ratio of nutrients. The amount of milk produced during this period also increases significantly. You can produce 600-700 ml per day, 5 which is a very impressive volume compared to the small amount of colostrum that was produced in the first days.
“The composition of milk in all mammals varies depending on the needs of the cubs”
Your breasts are now in the “build-up” mode: the body learns to make milk in the amount that the baby needs. Breasts become more mature, like milk. Compared to colostrum, transitional milk contains more fat and lactose — a natural sugar that gives your baby energy.
“Lactose levels rise sharply in the first two to three days after giving birth,” says Professor Hartmann, “Changes also occur in the composition of fats: the content of fatty acids with an average chain length of C10 and C12 increases. They are an easily processed energy source and have antiviral properties. In addition, sodium and chloride levels are greatly reduced during this period, so milk has a very low salt content. ”
Protein: the right ratio
The protein content in breast milk also does not remain unchanged. There are two types of proteins in human milk: casein and whey. Under the influence of acid in the child’s stomach, casein turns into a solid mass (cottage cheese) and gives a feeling of satiety for a longer time. It also has antimicrobial properties. Serum is rich in antibodies and remains liquid, so it is easily absorbed, which is especially important for newborns. As the child’s gastrointestinal tract strengthens, the ratio of casein to serum in milk gradually changes. If in colostrum it is about 90:10, then in a month it reaches 60:40, and after a year of breastfeeding a balance is established at the level of 50:50.
This protein ratio is ideal for humans, because our body grows relatively slowly, and the brain is constantly growing and becoming more complicated. In addition, it contributes to the intake of all the necessary amino acids that the child needs for the healthy development of the brain, eyes and other organs.
The amount of whey protein in human milk is significantly higher than that of other mammals. In cow’s milk, the ratio of whey and casein is the opposite: 20:80 (therefore, it is not suitable for feeding children up to a year).
“Milk is created to perform a specific task,” Professor Hartmann continues. “Some components are present in any milk – for example, proteins and fats – but if you look at what proteins and fats are, it becomes clear which animal belongs to milk. The composition of milk in all mammals varies depending on the needs of the cubs. ”