Personally, I hate sleeping with a bra on. There are few things more uncomfortable for me than feeling the underwire as I toss and turn while I'm trying to get some rest. There have been studies about the dangers of wearing a bra and how it is linked to cancer. On the other side of the argument, however, many claim that the extra support will prevent sagging (Marilyn Monroe was known to do this) or it just doesn't do any harm. So which one is it?
According to an article in The Huffington Post, the answer is actually more neutral. "There is certainly no evidence that sleeping in bras is either helpful or harmful," Amber Guth, MD, associate professor of surgery and director of the Breast Cancer Surgery Multidisciplinary Fellowship at NYU Langone Medical Center, tells the site. "Sagging or changes in the breast are due to a number of factors: Pregnancy and breastfeeding being the most common causes, along with time and gravity."
It's all about how well your bra fits you. According to an article on Cosmopolitan UK, a tight bra restricts blood flow and can affect the lymphatic system. "A tight bra may restrict the flow of lymph to the many important lymph nodes around the breast and armpit, hindering the system's vital function of flushing toxic waste-products from the body," Seth Rankin, MD, founder of private GP chain London Doctors Clinic, tells the site.
Rankin also believes that wearing a bra to sleep has little to no effect on preventing sagging. "Breast sagging is an inevitable fact of life for women as they age," he tells the site.
So while sleeping with a bra that fits you correctly and isn't too tight may not do that much harm to you health-wise, there aren't too many benefits either. If you need the extra support to feel comfortable and have gotten your bra fitted well, continue what you're doing. As for me, I'm going to continue sleeping bra-free.