Milk donor perceptions of the acceptability of breastmilk as a tool in breast cancer research: a qualitative study

Abstract Breastmilk is a highly complex biofluid, essential for early infant nutrition. The benefits of breastfeeding for maternal and infant health are extensive and well established. In addition to this, breastmilk holds potential as a biomedical research tool, providing a window of opportunity to study maternal health and diseases, such as breast cancer, through investigation of breastmilk components, immune factors, microbiome and live cells that can harbour precancerous changes. However, the prospect of using human milk for biomedical research raises important considerations, as experiences with breastmilk are personal, emotional and relational dimensions. This is the first known study to explore how UK milk donors feel about donating breastmilk for research and using it to detect health issues. Acknowledging research participants views is essential for sensitive and relevant research and effective communication of research findings. Breastmilk donors were invited to semi-structured one-to-one interviews to explore perceptions of breastmilk as a biomedical resource and its use in health research and disease detection. Thematic analysis was conducted to identify themes from interviews. Participants expressed surprise and intrigue at the idea that breastmilk could be used in biomedical research. Breastmilk was primarily associated with infant health rather than as a tool to provide insight into maternal health and disease. Breastmilk research was seen as a natural and non-invasive, yet finite way to study breast cancer risk. Knowing that pre-cancerous changes could be detected in breastmilk elicited mixed reactions, from optimism about early breast cancer detection to discomfort about impact on infants. Breastmilk research may impact maternal decisions to initiate or continue breastfeeding, although other factors were highlighted as more likely key decision makers. Breastmilk is an underutilised and understudied resource in women’s health research. The current study highlights the tension between the duality of breastmilk as both an innately personal, nutritional substance for infant feeding and as a biomedical resource, illustrating the ethical and emotional complexities surrounding its use in research. These insights underscore the need for clear communication, education, and public engagement to ensure that future breastmilk research respects milk donor autonomy and emotional connection to their milk, while also advancing women’s health research.