A new study into why some women do not produce enough quantities of breast milk has indicated that the cause is the hormone insulin, which affects the amount of milk.
Quantities of breast milk are low in some mothers because the human mammary gland becomes highly sensitive to insulin during lactation (the production of milk). Specifically this relates to a the glucose metabolism which works different in some women compared with others.
Women who struggle to produce sufficient quantities of breast milk tend to have different characteristics to the majority, such as being overweight, being at an advanced maternal age, or having a large birth-weight baby.
According to the research report, Dr. Nommsen-Rivers, the lead scientists behind the project, indicates that the breast should be thought of as a 'biofactory' that manufactures massive amounts of proteins, fats and carbohydrates for nourishing the newborn baby. For the production of the these nutrients, insulin plays a role.
Insulin is a peptide hormone central to regulating carbohydrate and fat metabolism in the body.
The research was undertaken by the Cincinnati Children's Hospital Medical Center and the University of California Davis medical staff. A paper has been published in the journal PLOS ONE. The paper is titled "RNA Sequencing of the Human Milk Fat Layer Transcriptome Reveals Distinct Gene Expression Profiles at Three Stages of Lactation".