Centering human milk composition as normal human biological variation

Abstract

Objectives: Human biological variation in the phenotype is the cornerstone of modern human biology, evolutionary anthropology, and related studies of human evolution. Minimal dialogue, however, has considered human milk to be part of this phenotypic variation. This may reflect researcher bias-mental models oriented around commercial infant formula and homogenized cow's milk, both of which present milk composition as static. A general lack of research outside primarily Western, well-nourished populations has also contributed to this underestimation of biological variation. Methods: This review analyzes published research on breast milk composition, developmental metabolic programming, and maternal body composition to articulate the ways in which population-based studies of human milk outside the United Sates are necessary to better understanding biological variation in human milk phenotypes. Results: This review discusses some of the common issues in current research on the biological variation in human milk composition and argues that anthropological inquiries that frame milk as part of an adaptive phenotype are necessary to better understand the biological significance of human milk composition in the production of human biological variation. Conclusions: Biological anthropology is uniquely positioned to investigate biological variation in human milk, using evolutionary theory, cutting edge biology, and anthropologically informed perspectives that challenge the biomedical framing of lactation and often act to privilege well nourished, primarily western populations and formula feeding as normatives for infant feeding research.

Maternal weight status and the composition of the human milk microbiome: A scoping review

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Evolutionary biological perspectives on current social issues of breastfeeding and weaning

“…Peer‐to‐peer online breast milk sharing is widespread in some regions such as the U.S. (O'Sullivan et al, 2018), yet it is also clear that there is little involvement of healthcare professionals as an information source in the community (Perrin et al, 2016). Breast milk is also a signaling substance that transmits information about environmental and physiological conditions between mothers and infants for their developmental programming and immunological protection (Ganal‐Vonarburg et al, 2020; Miller, 2020; Nguyen, 2020; Quinn, 2021). Regardless of the route of the trade, the signaling function of breast milk can work in a different context when another infant consumes milk that has been separated from a particular mother‐infant pair (Palmquist, 2018).…”

Minimally invasive biomarkers in human population biology research, part 2: An introduction to the special issue

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