Breast milk is not just food. At first glance, it is a mixture of fats, proteins and sugars capable of feeding the newborn, but there is much more than that. Its composition is so complete and complex that it has not yet come to study everything that treasures this authentic biological gold, an intelligent substance that is adapted to the needs of the baby at each stage of growth.
Through the breast milk, the mother passes the baby vitamins and other nutrients, but also passes other more complex substances, such as glucocorticoid hormones, including cortisol, a hormone secreted by the body in response to stress and anxiety.
It is logical to think that by transmitting high levels of cortisol through breast milk, this influences your temper in some way. And this has been proven by a group of researchers from the University of California.
Cortisol present in breast milk influences the temperament of the offspring
The researchers conducted the experiment with a group of rhesus monkeys from the California National Primate Research Center to study the relationship between the amount of cortisol circulating in breast milk and the temperament of the offspring.
To do this, they obtained samples of breast milk at different times, associated with milestones in the development of the offspring and in the synthesis of the mother's milk. The concentration of cortisol in milk was measured when the pups began to conduct behavioral exploration beyond their mother, which occurs at the first month of age, and then in the peak of breastfeeding, corresponding to 3.5 months of age.
First time mothers, higher cortisol level
In order to define the temperament of the offspring, an observation pattern already experimentally validated was used, in which 16 specific characteristics of the study animals were recorded, during an observation period of 25 hours.
The first thing they observed was a very interesting fact: mothers who had had few or no offspring showed high levels of cortisol in their milk, compared to those females with whom they had had a greater number of children.
A more cortisol, more nervous and less confident offspring
Then, they analyzed the level of cortisol present in mothers in the two stages of breastfeeding, both in female and male offspring.
In female offspring, the higher the level of maternal cortisol in the first month of breastfeeding, the more likely the offspring will show a nervous temperament, while measuring it at 3.5 months, it also predicted a less confident temperament.
In male offspring, it is not the level of cortisol in their mothers' milk that correlates with their temperaments, but the changes in cortisol levels measured in the first month and at 3.5 months of lactation: by increasing cortisol during breastfeeding was observed in male offspring a higher nervous temperament, while, if cortisol decreases through breastfeeding, a confident temperament.
Relaxed mothers, calm babies
It is not the first time that we are concerned about this issue. On another occasion we had already wondered if mothers can pass their children 's nerves and stress through breast milk. This study was not yet known but others equally revealing made us think that it is indeed so. If mothers are nervous, children will be too and if they are relaxed, babies will also be calmer.
This new study from the University of California is an interesting example of how we can pass babies through milk substances that interfere with their metabolism and influence their temperament in some way.
