Mother's Milk, Nutrients, And A Message Too By Carl Zimmer

The article I chose is titled “In a Mother’s Milk, Nutrients, and a Message, Too,” it was written by Carl Zimmer, and published on November 6, 2014. Zimmer elaborates on how a new study has found out that mother’s milk does not only provide the newborn with essential nutrients, but also transmits messages to the infant. The study published by the journal Ecology shows that cortisol, a stress hormone, is often transmitted from the monkey mother to its baby through breast milk. It was demonstrated that cortisol, produced by the mother, is transmitted to the offspring through milk and they develop receptors in response. Moreover it was found out that babies feeding on milk with cortisol gained more weight than those who received milk without it. Why? As Zimmer explains, researchers discovered that the amount of cortisol produced by a macaque monkey mother was correlated with the number of offspring she had had. The more offspring a mother had had, the less cortisol levels she presented. As it turns out, new mothers present higher stress hormones levels, as they are inexperienced in nursing newborn babies and they can’t provide their child with as much energy as an experienced mother would. The cortisol that the inexperienced mother produces tells her newborn (through breast milk) that it should not expect a great amount of nutrients; thus all of its energy should be directed to gaining weight (and not wasted in other activities). Consequently these monkeys grow faster despite having fewer resources.

Zimmer states that discoveries like this one might lead to changes in the milk formula. “Right now, manufacturers try to replicate the nutrition, and even the microbes, in natural breast milk. But they may also need to consider the messages the formula is — or isn’t — sending”