False. Bras, even underwire bras, do not in any way increase a woman's risk of developing breast cancer. As Scientific American explains, this is a myth that sprung up in the mid-'90s after a pair of medical anthropologists claimed that by inhibiting "lymphatic drainage" bras somehow trapped toxins in the breast tissue, which led to cancer.
But while that claim still floats out there in the wilds of the internet, no credible research backs, or has backed, the idea that wearing a bra ups a woman's cancer risk.
"The overall consensus among doctors is that neither the type of bra worn nor the tightness of undergarments has any connection to the risk of breast cancer," The Unversity of Arkansas for Medical Science's web site explains.
First, we were told that the average bra size in the U.S. was a 34B, then we were informed that it's now a 36C. And while bra manufacturers certainly can track the sizes that consumers buy the most, bra fit experts say there is no true "average" bra size, largely because bras vary so much from model to model and from brand to brand that any true estimates are virtually impossible to ascertain. "Bras are like jeans," said Kim Caldwell, a bra fitter with Linda's Bra Salon in NYC. What fits in one pair may be totally wrong in the next.
Anecdotally, Caldwell said that most common size Linda's sells in store are 32F and 34G.
Some women maintain that wearing a brassiere while catching ZZZs helps keep their breasts perky, but that's not the case. (Nor is it the case that sleeping in a bra will harm your breasts in any way, explained Dr. Carlos Burnett, a plastic surgeon who practices in New Jersey, although many women find it downright uncomfortable.)
The so-called suspensory ligaments aren't getting stretched out significantly while you're asleep in your bed, Burnett said, so whether you wear a bra or not doesn't much matter either way.
Caldwell is surprised by how frequently she fits women who think that wearing a bright white bra under a white shirt is the least visible option.
"The closest you can get to your skin tone, the more invisible the bra will be under clothing," she explained. Which means nude-tone bras are your best bet if you're looking to go incognito. And it also means that women with darker skin tones should look for darker bras that closely match their coloring. For a long time "nude" coloring really meant "nude-only-if-you're-a-fair-skinned-white-woman," but increasingly companies are making nude models that take into account that women come in many different colors besides beige, Caldwell said.
Things got a little nutty last spring when French researchers published a study claiming that bras provide no benefits to women's breasts and, in fact, may actually cause them to sag more over time. They looked at the breasts of more than 300 women, age 18 to 35, over the course of 15 years.
But experts say it's too soon to get behind the idea that bras make women's breast droop more so than going bra-free does. First, the French researchers measured the distance between the clavicle to nipple, Burnett said, but they didn't measure the distance to the base of the breast. Women's nipples often stay in much the same place as they age, while the bottom of the breast droops. Plus, as an earlier HuffPost article pointed out, the French study did not take into account women's breast size.
It's generally thought that bras can help keep breasts perky by supporting the suspensory ligaments, Burnett said, and keeping those ligaments from stretching out with constant movement of the breasts.
It's not the cups, it's not the underwire and it's not the straps that do most of the hard work in terms of lifting your breasts -- it's your bra's band. The straps are there simply to help keep the cups flush to the body, Caldwell said, while the band provides 90 percent of the support. Thus, you really want to find a band that hugs your body and stays in place when you move around, Caldwell said. Which surfaces another myth: There's no magic bra out there that can somehow get rid of the "back spillover" that some women dread. Because you need your bra band to be snug -- not choking you, but really snug -- it's inevitable that most of us are going to have a bit of a line.
"Unless you're an Olympic swimmer, you're going to have it," Caldwell chuckled. "It's an elastic going around your body and hugging you." Basically, there's no reason to get upset over a tiny bit of spillover, she said. "Your bra's job is to keep you lifted."
Oh, how we wish this last one were true. But Caldwell -- and most bra-fitting experts -- agree that bras have a relatively short shelf life, somewhere around 6 to 9 months.
Caldwell knows how that sounds. "I say that, and everyone's like, 'What?!'" But a lot of factors influence how long a bra can remain in tip-top shape: they should be hand-washed with the right soap, stored gently and given regular breaks. If you rotate two bras, they're going to wear out a lot faster than if you rotate several. And good news for the small-chested among us: Smaller bras tend to last a bit longer as well, because the band isn't stretching as much, Caldwell said.
But even if you adhere to all of those best practices, the most you can really ask from a bra that you wear with any regularity is about one year, she said. Guess it's time to go bra shopping...