BRAS do nothing to help support a woman’s breasts and could even be doing damage.

Professor Jean-Denis Rouillon of Besançon CHU found in a 15-year study of 330 women that “medically, physiologically and anatomically” breasts gained no benefit from their weight being supported in a bra.

Breasts would gain more tone and support themselves if no bra was used. Using a bra meant “supporting tissues will not grow and even they will wither and the breast will gradually degrade”.

Some of the women who took part in the experiment told France Info that stopping using a bra had even helped ease back pains.

However, Prof Rouillon said: “It would be dangerous to advise all women to stop wearing their soutien-gorge as the women involved were not a representative sample of the population.”

He said his initial results “validated the hypothesis that the bra is a false ‘need’” but women who had been wearing bras for a long time would not gain a benefit from stopping now.

Prof Rouillon has been carrying out his experiment since 1997; measuring and examining their breasts to study the effects of living without the support of a bra.

He said a principle observation was that the nipple would lift 7mm in a year towards the shoulder in those women not wearing a bra. The breast would also become firmer and stretch-marks faded. He suggested that girls who started wearing a bra once their breasts first started to appear would soon become dependent as the supporting muscle structure would degrade.