The Evolution of the Mammary Gland and the Milk It Produces

In our lead article, “The Evolution of Immune Functions of the Mammary Gland and Protection for the Infant” by Armond Goldman, ¹ we learn the developmental history of the human mammary gland. Human milk is for the human infant. We knew that! But did we know that immune protection provided in human milk evolved over the millennia? The protection provided has adapted to the changes in climate, in the environment, and in microbial flora in the human just as it has for other species. Human milk continued to adapt during the industrial revolution and the development of closed communities, keeping the newborn safe during all these new challenges. The interplay between the many agents in human milk makes it impossible, according to Goldman, to add an isolated defense agent to artificial milk formula and duplicate the protective effect of human milk. The synchronization of the biologic benefits provided by the baby's own mother matches the timing of the infant's own immune system development.

Goldman also points out that milk from each species changes quantitatively and qualitatively with the duration of lactation. The developmental delays in the immune system of the human infant are compensated for by the mammary gland as it provides the necessary protection. It is clear the breast has been specifically designed to provide not only nourishment but also life-saving protection against the environment for the human infant. This review confirms that breastfeeding is the best nutrition and protection for the human infant.

Inordinate amounts of time and money are being spent to alter the milk of another species for the human infant while the perfect answer, mother's own milk, is being ignored. With considerably less time and money, an international effort could be launched to educate and support women to provide their own milk. The data continue to mount as to the value of mother's milk nutritionally, immunologically, and developmentally and in the prevention of infections, obesity, allergies, and many chronic diseases.

The American Academy of Pediatrics ² has firmly stated that infant nutrition should be considered a public health issue and not only a lifestyle issue. What will it take to persuade women to accept their biologic role? Healthcare professionals will need to educate the public and reverse this trend. It can start with a huge parade of healthcare professionals crying out with one voice: Human milk is for human infants.