No, but the idea that it can is a persistent misapprehension probably arising from wide publicity given a pronouncement in 2013 by a professor at a small French university. Jean-Denis Rouillon, whose field is sports medicine, claimed to have spent 15 years on a study of the anatomy of more than 300 women before reaching a “preliminary conclusion” that bras make breasts sag. In a radio interview he maintained that wearing a bra weakens muscles that hold up the breasts. Rouillon’s work has not been published, so all we know is what he said in interviews at the time. Even today (four years later), we’ve seen no evidence to support his claims.
The truth of the matter is that over time, women’s breasts will sag. These effects stem from gravity, a loosening of the ligaments that help breasts keep their shape and the gradual replacement of breast tissue by fat. Genes play a role, as do pregnancies. A study at the University of Kentucky College of Medicine, published in 2008, found that the risk of breast sagging increases with each pregnancy, although breastfeeding does not seem to make matters worse. The researchers also found that getting older, smoking, having a high body mass index and a larger prepregnancy bra size were independent risk factors for breast sagging.
As for bras, wearing a push-up bra can’t prevent sagging, but it is important to wear a sports bra during exercise – particularly running – since the combination of gravity and movement can stretch breast tissue and over time.
If you’re worried about sagging, you may be able to counteract it by exercising your chest muscles – push-ups are considered particularly effective. You can find descriptions online of other chest exercises that may help elevate your breasts.
While we’re on the subject, I should note that massaging olive oil into your breasts won’t prevent or reverse sagging. The notion that it can comes from an unsupported online claim that the antioxidants and fatty acids in olive oil can prevent sagging breasts. No source was given for this claim, and I’ve seen no evidence that any oils or lotions applied to the skin can prevent or reverse the problem.
If you are determined to do something about sagging breasts, the most reliable option is surgery. A breast lift (mastopexy) reshapes breasts by raising them, removing excess skin and tightening the surrounding tissue. According to the American Society of Plastic Surgeons the demand for this procedure has grown 70 percent since 2000 outpacing breast implants 2-to-1. This is an expensive option, averaging $4,636, which doesn’t include anesthesia and hospital costs.
Andrew Weil, M.D.
Brian D. Rinker et al, “The effect of breastfeeding on breast aesthetics.” Aesthetic Surgery Journal, September/October 2008, doi: 10.1016/j.asj.2008.07.004