No, bras do not cause breast cancer.
The idea that bras, particularly underwire bras, somehow increase the risk of breast cancer is a persistent myth – one cancer education groups have tried to dispel for years. A new study may help bust it for good.
The study, published Friday in Cancer Epidemiology, Biomarkers & Prevention, found no differences in lifetime bra-wearing habits among more than 1,500 postmenopausal women with and without a history of breast cancer. It did not matter whether the bras had underwires, how many hours a day they were worn or at what age women starting wearing them. It also did not matter if women were heavy or thin, A-cupped or D-cupped.
"There is no evidence that wearing a bra increases a woman's risk of breast cancer," says Lu Chen, a researcher at Fred Hutchinson Cancer Research Center in Seattle.
Chen led the study as part of a broader look at risk factors. She was not surprised, she says, that "there's just nothing there."
There isn't even a plausible theory on why bras would increase the risk, she says. But higher breast cancer rates in developed countries – where bra-wearing is most common – had led to speculation that there might be a link. One idea, unsupported by any research, was that bras might block the flow of fluid through the lymph system, impeding the removal of cancer-causing wastes and toxins.
The only previous scientific study on the question found no statistically significant links. The study did hint at a link in younger women, but researchers at the time said they doubted any direct cause and effect. Instead they noted that obese women were both more likely to wear bras and to get breast cancer, making weight the real link. Obesity is a risk factor for breast cancer, according to the American Cancer Society.
The 1991 study included some women who never wore bras. The new one does not, because researchers found only one such woman among Seattle-area subjects, Chen says.
In a 2002 survey conducted by the cancer society and Discovery Health, 6% of adults agreed that "under-wire bras can cause breast cancer,'' and 31% were unsure.
Ted Gansler, the cancer group's director of medical content, said in an e-mail that the new study "should reassure women that they can safely ignore this matter."
The bra myth is not harmless, he said. For women without breast cancer, it could cause "anxiety and distraction from proven strategies for prevention and early detection." For women with breast cancer, he said, it "might be a source of guilt."