October 13th is National No Bra Day, invented to promote breast cancer awareness and to help raise money for research.

Bras are a divisive symbol; some consider them a ludicrous invention, others as a tool for emancipation. Scientifically speaking, the most notorious research on bras and breasts came out a couple of years ago.

Sport science researcher Jean-Denis Rouillon, a professor based at the University of Franche-Comte in the eastern town of Besançon, led a team that conducted a 15-year study on the effect of bras on 330 women aged 18 to 35.

The study was conducted at the Centre Hospitalier Universitaire (University Hospital) in Besançon, and the team used a slide rule and a caliper to record the changes to the women's breasts year in and year out.

The findings suggested that wearing a bra from an early age did nothing to help support the chest, reduce back pain or prevent breast sagging. “Medically, physiologically, anatomically – breasts gain no benefit from being denied gravity. On the contrary, they get saggier with a bra,” Professor Rouillon told France Info in an interview.

The researchers believe that young women would gain more tone and supporting breast tissue if no bra were used. In the study, women that stopped wearing bras – through choice, not as a requirement of the study – had a 7-millimeter (0.3-inch) lift in their nipples when compared with regular bra users. Bras, they claim, could hamper circulation and reduce breast tone over time.

"For younger women, not wearing a bra will lead to increased collagen production and elasticity, which improves lift in a developing breast," said Dr. Stafford Broumand, who was not connected with the study, for Refinery29. Of course, many women wear bras for other reasons than to just reduce the sag of their breasts.

The team advises caution on drawing general conclusions from this research, as the women in the study are not representative of the population as a whole. Professor Rouillon believes more research is necessary to understand the potential impacts – positive or negative – that bras may have, and admits these are very preliminary results. Moreover, although the findings were scheduled to be published, IFLScience was unable to find the paper in the literature.

[H/T: Counsel & Heal]