Biological Anthropology Section

Society for Anthropological Sciences

Cosponsored - Oral Presentation Session

Reinterpreting Human Milk Cortisol in North American Women

Presenter(s)

• RA

  Rachael Anyim

  Clifford D. Clark Diversity Fellow
  SUNY - Binghamton University, Department of Anthropology

Co-Author(s)

Shanita Li (Binghamton University)
Daniel Armstrong (Binghamton University)
Rita Spathis (Binghamton University)
Katherine Wander (Binghamton University)

Lactation is an ancient adaptation that allows mammals to invest heavily in their offsprings’ survival. An instinctive and yet social phenomenon, breastfeeding facilitates the development of bonds between mother-infant dyads. Human milk content of nutrients, hormones, and immune factors is dynamic: changes in milk composition often occur to meet a breastfeeding child’s needs. Milk also contains the stress hormone cortisol; it is not clear how to interpret the presence of cortisol in milk, or fluctuations in milk cortisol, with regard to the breastfeeding child’s needs, and its benefit is unknown. Human milk can be used to convey information to the infant, with cortisol potentially playing a critical role in this signaling process. We estimated cortisol concentration in milk specimens from 48 nursing women recruited from the Binghamton, NY area. We did not find any evidence that milk conveyed information about mothers’ environmental stressors. Instead, milk cortisol increased each additional month of child age, over a span of 26 months. Among these relatively healthy and secure mother-infant dyads, we interpret this pattern in milk cortisol as a means to signal breastfeeding children to prepare for the conclusion of the breastfeeding period.