Estrogen is a hormone that is neces

Estrogen is a hormone that is necessary for the normal development and growth of the breasts and organs important for childbearing. It helps control a woman's menstrual cycles and is essential for reproduction. Estrogen also helps maintain the heart and healthy bones. However, a woman's risk for breast cancer is associated with lifetime exposure to estrogen. Understanding how estrogen works in the body, knowing about how chemicals in the environment can affect body estrogen levels, and how diet and lifestyle factors affect estrogen exposure over a lifetime, may help women make more informed decisions about their bodies and their environment.



Estrogen may be implicated in breast cancer risk because its role in stimulating breast cell division and its work during the critical periods of breast growth and development;