After all these years of thinking bras were helping our breasts defy gravity, a French researcher has evidence that the soutien-gorge is making breasts (gasp!) saggier. Professor Jean-Denis Rouillon used calipers to measure changes in the breasts of 330 women ages 18 to 35 over 15 years and found that wearing a brassiere actually prevents “supporting tissues” from growing and causes breasts to “wither” and “gradually degrade.” The study also found that bras don’t alleviate back pain—in fact, they make it worse. Rouillon’s findings have prompted a spirited debate over the merits of bras, with some commentators speculating whether the research could prompt a 1970s bra-burning revival. But before you ditch your favorite Victoria’s Secret push-up, take note: Rouillon said his research was “preliminary,” so you can keep your bra on—for now.