Prolactin is a hormone produced by the pituitary gland in the brain and it enables women to produce breast milk after giving birth. Occasionally women who have never been pregnant or given birth produce excessive amounts of this hormone and it can cause abnormal breast milk production.

New research has shown that gluten can act as an endocrine disruptor, meaning it can disrupt the normal production of prolactin by the pituitary gland.

The condition of excessively high levels of prolactin is called hyperprolactinemia. It is a fairly common problem and can disrupt the menstrual cycle and possibly impair fertility. In men, excessive prolactin can lead to abnormally low testosterone.

A study found that adoption of a gluten free diet can restore normal levels of this hormone in some individuals. This improvement is thought to be due to a reduction in inflammatory cytokines upon adoption of a gluten free diet.