Wearing a bra, especially a constricting one with under wires and especially to bed, prevent normal lymphatic flow and would likely lead to anoxia (lower than normal oxygen content), which has been related to fibrosis which has been linked to increased cancer risk.
In fact, all bras are generally constricting. On many women who wear them you can actually see dents around the sides of their chests where their bras have been even in something as opaque as a black T-shirt.
In the past primitive women evolved under conditions where there was breast movement with every step that they took when they walked or ran. Information in scientific literature on lymphatic flow indicates that this may be as important as the constriction factor.
Every subtle bounce of the breast while moving, walking, running, etc., gently massages the breast and increases lymphatic flow and thus cleans the breast of toxins and wastes that arises from cellular metabolism.
Although the link between a blocked lymphatic system and breast cancer still needs to be studied further, the hypothesis for this is extremely plausible.
The new theory of bra-wearing triggering breast cancer is even more compelling when one looks at the commonly accepted risk factors for breast cancer.
Age: The older the woman, the higher her chances are of developing breast cancer. This is highly logical in that she has had a longer period of exposure to toxins that have accumulated in the breast due to poor drainage.
Country or culture of origin: Breast cancer seems to be more of phenomenon in industrialized nations. People in some of the Third World countries do not have such high incidence rates of breast cancer. It appears that women from developed countries succumb to the lifestyle of bra wearing. This is not the case in some of the poorer nations where a large portion of women still go braless.
Studies have shown that the incidence of breast cancer in Japan was greater among urban dwellers. This could be linked to the fact that urban women subscribe to bra-wearing more than their rural counterparts. Different cultures in similar environments also experience different breast cancer rates. Native Americans, who typically do not wear bras, have breast cancer incidences similar to non-Western cultures.
Hormonal influences: Estrogen levels in a woman's body are normally higher before her period than at any other time during the month. This is the time that the women's breasts are naturally enlarged.
During this time when the breast are enlarged, the effect of breast constriction by a bra and the subsequent impairment to lymph drainage is most pronounced.
Childless or unmarried women: During pregnancy, the breasts enjoy greater blood supply and enhanced lymphatic drainage. The breasts of childless or unmarried women do not have a chance to develop fully.
Given this undeveloped drainage system, constriction of the breasts with a bra can cause further damage to an already limited drainage system.
Early first period: an early onset of menstruation leads young women to begin the adult lifestyle of wearing bras earlier on. The desire for even larger breasts can lead these young adults to wear padded or wired bras, thus constricting their undeveloped breasts. This longer exposure to bra wearing exposes the breasts to toxin build up.
Diet: It has been assumed that changes in diet cause an increased risk of breast cancer. However, we need to look further. Toxins are normally concentrated in the fatty portions of food. A higher intake of animal fats, contains milk, meat, poultry and cheese results in a higher consumption of toxins.
Also certain types of food that we like to eat may have been exposed to more toxins like pesticides. Bra-wearing then exacerbates the problem of breast disease by helping to concentrate toxins in the breast.
From the above, overall it can be seen that lymphatic drainage problems that may be caused by bras can explain most of the risk factors linked to the incidence of breast cancer.
