Women should continue to wear bras if they want to because there is no evidence whatever to associate bras with breast cancer. This theory was developed by Syd Singer and Soma Grismaijer who wrote a book called Dressed to Kill, claiming that bras constrict breast tissue and block lymph drainage, causing chemical toxins to remain in the breast. The Singers say that “because lymphatic vessels are very thin, they are extremely sensitive to pressure and are easily compressed.” Their press release claims: “Soma and Syd were struck by the low incidence of breast cancer in poorer nations awash in pesticides dumped by northern nations.” So their theory claims that bras constrict breasts, close blood vessels and lymphatics, and keep pesticides in breasts for along time, so the pesticides can then cause cancer.
They report that three out of four women who wear their daytime bras to sleep contract breast cancer. They claim that 80 percent of bra-wearers who experience lumps, cysts and tenderness will see those symptoms vanish, “within a month of getting rid of the bra.” However, there is no data in the scientific literature to show that women with larger breasts are more likely to suffer breast cancer; that wearing bras is associated with breast cancer; that constricting breasts causes pesticides to accumulate in breasts; or that avoiding bras gets rid of cysts or lumps in the breast.
The authors have not published their findings in medical journals, and I could not find any academic appointments at an accredited university for either of them. Their web site asks for contributions to support their research that they conduct from a 67-acre farm in Hawaii.