Similac Lacking Pheromones
I have described, with deep reverence, what is known about the complexity of breastmilk, and some of the factors that interfere with successful nursing: hospital-based birth and associated procedural interruptions of the mother-baby unit, hospital-based interventions and their endocrine-disrupting effects, lack of education around lactation support, conflict of interest in hospitals who receive free formula handouts, and physiological barriers such as insulin resistance, environmental estrogens from consumer products and industrial animal foods, and hypothyroidism.
Treating formula and breastmilk as bioequivalents is like saying that pizza contains all the food groups and is a nutritious meal.
In addition to complex and fluctuating fatty acids, bacteria, nutrients, and even exosomes containing microRNA immune information, breastmilk has been recently determined to communicate stress-related information to the infant.
Analysis of 108 rhesus macaque monkeys revealed the transmission of pheromones – hormonal communication between humans – like cortisol, in varying amounts, primarily correlated with birth order (high cortisol transferred with first and earlier infants in the birth order). This transfer primes the gut for cortisol receptivity, early establishment of the gut-endocrine-brain connectivity.
The babies fed high-cortisol milk develop a nervous temperament, focusing their limited energy on putting on weight. As a result, they grow faster, despite getting less energy from their inexperienced mothers.
While these results are not readily extrapolated to human infant/breastfeeding dynamics, they serve to affirm a growing appreciation for the irreplaceability of evolutionary processes and the imperative to protect rather than outsmart our native physiology.