Debunked claims linking bras to breast cancer resurface online

"These Two Types Of Bra's Are More Likely To Cause Breast Cancer Than Any Other," says David Wolfe, an American author and raw food advocate who has previously promoted misinformation, in a June 16, 2023 Facebook post.

Wolfe cites a blog post suggesting bras decrease the body's ability to drain lymph and that metal underwires attract magnetic fields, thus increasing cancer risks.

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Screenshot of a Facebook post taken June 23, 2023

Similar claims appeared on Facebook, TikTok and Twitter, where one user said: "#1 cause of breast cancer is constricted, squashed breasts from wearing bras that are too tight that restrict blood and lymph circulation."

The claims appear to stem from a 1995 book written by a medical anthropologist and a 1991 study showing lower breast cancer rates in premenopausal women who do not wear bras.

But no research has found a causal link between breast cancer and bra-wearing -- and numerous experts have refuted the claim over the years.

"No matter what the type, bras do not cause cancer," the National Breast Cancer Foundation says on its website (archived here).

"There is no evidence to support the myth that lymph fluid is restricted when wearing an underwire bra (which sparked this myth decades ago) or any other type of clothing, although bras that do not fit well can cause discomfort and swelling."

A 2014 study (archived here) also found no link between breast cancer and bra-wearing.

"No aspect of bra-wearing, including bra cup size, recency, average number of hours/day worn, wearing a bra with an underwire, or age first began regularly wearing a bra, was associated with risks of either (invasive ductal carcinoma) or (invasive lobular carcinoma)," the researchers said.

The authors of the 1991 study that found a lower rate of cancer among women who do not wear bras said this was "possibly because they are thinner and likely to have smaller breasts."

The National Center for Health Research says on its website (archived here) that "even if women who wear underwire bras are more likely to be diagnosed with breast cancer, a likely explanation would be that many women with larger breasts also tend to be heavier."

"Being overweight or having a lot of body fat puts a woman at increased risk for breast cancer," the nonprofit says. "The bottom line: well-designed studies have not convinced experts that wearing bras or underwire bras increase your chances of developing breast cancer."

Erica Mayer, a breast oncologist at the Dana-Farber Cancer Institute, told AFP on June 23 that there are other things people can do to stay healthy.

"Pursuing a healthy lifestyle, including exercising regularly, maintaining your weight and limiting alcohol may be helpful in reducing breast cancer risk," Mayer said in an email. "Women should discuss with their provider if additional strategies including medications may be indicated to help reduce risk."

AFP has fact-checked other false and misleading claims about cancer here, here and here.