Scientific evidence does not support the claim that using bras makes breasts sag

Currently making the rounds on Instagram is a video with nearly 3 million views in which Noemí Casquet, an influencer and journalist specialised in sexuality, claims that “a number of studies” have shown that wearing an underwire bra makes breasts sag because “it weakens the muscles that hold up the breasts”. 

This claim is FALSE. The influencer cites a 2013 article published in Medical News Today as her source, which repeats the claims of an alleged study carried out by a French doctor who claimed to have studied the effects of wearing a bra in over 300 women. However, the study was never published.

Verificat found no solid evidence in the scientific literature that using a bra makes breasts sag. This was corroborated in an email sent to Verificat from Ana Boldó, head of Gynaecology and Obstetrics Services at the Hospital Universitario de la Plana in Valencia.

“There are several studies that show that using underwire bras weakens the muscles that hold up the breasts and that, as a result, promote breast sagging.”

The article with which Noemí Casquet justifies her statement describes the results of a supposed study carried out over 15 years in France, which analysed the effects of wearing a bra in 320 women who did sport between 18 and 35 years of age. However, the study was never published, which is why no peer review had been carried out to guarantee its quality and no details are known about it.

Nevertheless, the preliminary results spread like wildfire in 2013 in national and international media following an interview that Jean-Denis Rouillon – the scientist at the University of Franche-Comté behind the study – gave to a student-run radio station, according to Reuters. Rouillon warned, however, that his findings were not generalizable to all women due to the limited sample and the preliminary results of the work.

Beyond this anecdotal case, a search for studies in the scientific literature only yielded one Japanese study carried out in 1990 with 11 women, which concluded that wearing bras did, indeed, contribute to sagging breasts. However, the sample size, the lack of a control group, and a methodology that did not consider other factors that might have influenced the results, do not allow solid conclusions to be drawn either.

In fact, PubMed – the most important database in biomedical literature – yields 23 results when an advanced search is made that includes with the terms “bra” and “ptosis” (the scientific term that describes the sagging of breasts).  

The only result related to the topic identified the following risk factors in the development of breast ptosis: age, significant weight loss, body-mass index, bra cup size, number of pregnancies and tobacco use. The variety of factors that play a role in breast sagging is also something that Casquet explains in her video, citing age among others.

“There is no evidence about the influence [of bras] on sagging breasts and breast atrophy, which is why there is no official position in favour of or against their use”, Boldó stated in her email to Verificat. In other words, there is also no evidence that using a bra prevents breasts from sagging, so their use depends on each individual’s own criteria and comfort.

The expert points out, however, that “prolonged use of underwire bras may have potential side effects on health that are only reported in non-scientific publications and surveys in which, depending on the wearer, there is a possibility of pain due to the skin being irritated by the underwire as well as pain in the chest area and below the arms”. To Boldó’s mind, these factors “seem to have more to do with choosing a design or size that does not suit the wearer”, making bra choice important for minimising discomfort.

Verificat has attempted to contact the influencer for more details, but at the time of publication of this fact-check, we had not received any response.