The bra-cancer link is not new. Doctors knew bras were causing breast cancer as far back as the 1930’s.
For example, Dr. John Mayo, one of the founders of the Mayo Clinic, wrote in the article “Susceptibility to Cancer” in the 1931 Annals of Surgery, that “Cancer of the breast occurs largely among civilized women. In those countries where breasts are allowed to be exposed, that is, are not compressed or irritated by clothing, it is rare.” A bra patent in 1950 stated, “Even in the proper breast size, most brassieres envelop or bind the breast in such a fashion that normal circulation and freedom of movement is constricted. Many cases of breast cancer have been attributed to such breast constriction as caused by improperly fitted brassieres.” (Taken from the 2018 edition of Dressed to Kill.)
The issue has to do with constriction from tight bras and the effect this has on lymphatic circulation, which is the immune system. The purpose of bras is to alter breast shape, and to do this the bra applies constant pressure to the breasts, which interferes with lymphatic circulation. Wearing tight bras compresses and constricts these delicate lymphatic vessels, preventing the proper elimination of fluid and toxins from the breasts, and impairing immune function and the ability to fight developing cancer cells. Essentially, bras cause chronic, mild lymphedema of the breasts which causes breast pain, cysts, and can lead to cancer..
This causes fluid and toxins to accumulate in the breasts, which results in breast pain and cysts. It also prevents the proper cleansing of the breast tissue, resulting progressive tissue toxification.
Keep in mind that the lymphatic system is the circulatory pathway of the immune system. Without proper lymphatic drainage, the breasts cannot be effectively cleansed of waste products, cancer cells, viruses, bacteria, cell debris, and other products that are normally flushed away.
Lymphatic impairment is immune impairment. It also increases cancer development.
The breast tissue gets deprived of oxygen and nutrients, as well, when the lymphatics are impaired. And any toxins we consume in our polluted air, water and food, as well as toxic medications, cannot effectively be flushed away from the breast tissue when the breasts are constricted by bras. Some of these toxins are also carcinogenic. The bra concentrates these toxins in the breast.