There is a surprising amount of misinformation circulating about what a brassiere does and doesn't do.
Huffington Post decided to do a little digging and debunk some of the biggest bra myths out there.
Firstly, the myth about bras trap toxins, up cancer risk is absolutely 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.
Second myth is that the average size is a 34B.
It's believed that the average bra size in the US was a 34B, then we were informed that it's now a 36C.
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.
Some women maintain that wearing a brassiere while sleeping 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.
Bras don't make your breasts sag.
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.
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, while the band provides 90 percent of the support.
A good bra does not last a lifetime. Most bra-fitting experts-agree that bras have a relatively short shelf life, somewhere around 6 to 9 months.
