From Mind to Milk: The Influence of Psychological Factors on the Composition of Human Breast Milk

Abstract

Background/Objectives: Breast milk is a complex fluid crucial for infant development, nutrition, and immunological and neurodevelopmental support. Recent findings suggest that factors regarding mental health, such as stress, anxiety, and postpartum depression (PPD), may influence the composition of breast milk. This review aims to synthesize current knowledge regarding the relationship between a mother’s mental state and the biochemical profile of human milk, focusing mainly on nutrients, hormones, immune factors, and microbiota. Methods: A systematic literature search was conducted in PubMed and the Web of Science using predefined keywords related to psychological factors and milk composition. Studies involving validated psychological assessment tools and only human subjects were included, in accordance with PRISMA guidelines. Results: Findings indicated that maternal stress and PPD are associated with alterations in breast milk composition. Elevated cortisol and changes in melatonin and prolactin levels have been observed. Immune components, such as secretory immunoglobulin A and transforming growth factor beta 2, exhibit variable responses depending on stress type and duration. Lower concentrations of docosahexaenoic acid and polyunsaturated fatty acid have been observed among mothers diagnosed with depression. Additionally, maternal psychological distress may influence infants’ gut microbiota composition, potentially affecting long-term health outcomes. Conclusions: The maternal psychological state plays an essential role in shaping the composition of human breast milk. Understanding these associations highlights the need for mental health support during the postpartum period to optimize infant development. Future research should focus on the molecular mechanisms underlying these changes and potential interventions to mitigate adverse effects.