Hormones in human milk: a summary of the quantity, determinants, and health outcomes of milk hormones

Lactation offers several health benefits to children, including lower risk of cardiometabolic disease and immune system development. These benefits have been attributed to composition of human milk, which contains bioactive components in addition to nutrients. Several metabolic hormones have been identified and quantified in human milk, including insulin, adiponectin, leptin, ghrelin, cortisol/cortisone, resistin, obestatin, apelin, nesfatin, insulin-like growth factor-1, and epidermal growth factor. Milk hormone concentrations fluctuate throughout the postpartum period and differ according to maternal biological factors such as BMI. These human milk hormones may play a role in infant growth, development, metabolism, and other longer term health outcomes.