Merilyn Monroe slept in a bra to keep her assets firm and perky, according to Hollywood lore. A new study out of France suggests it might have been more effective for the screen goddess to go "au naturel" instead.

Researchers spent 15 years studying the breasts of over 330 French women, and concluded that wearing a bra does not prevent sagging or ease back pain as commonly thought. "Medically, physiologically, anatomically—breasts gain no benefit from being denied gravity, Professor Jean-Denis Rouillon, from the University of Besançon, told France Info Radio. "On the contrary, they get saggier with a bra."

Taking measurements with a caliper, the researchers found that by not wearing a bra, muscles around the breast actually strengthened and the "nipple raised 7mm per year toward the shoulder." However, the scientists did not recommend all women abandon their bras since their muscles had probably already degraded.

While the phenomenon of "bra burning" has been greatly exaggerated, in 1970s it was not only politically correct but also fashionable to go braless in the United States. Since then, women have been trussing themselves into increasingly structured—and expensive—undergarments. According to Business Week, the women's intimates' industry generates over $11 billion a year in revenues.

The results of the study may be intriguing, but it's doubtful that droves of American women are going to ditch their bras anytime soon. For one thing, a study by the Center for Talent Innovation found that women who jiggle around the work place are deemed less worthy to become executives by both men and and other women.lol

Furthermore, the study focused on women ages 18 to 35. According to France's English-language news site The Local, one 28-year-old participant reported multiple benefits: "I breathe more easily, I carry myself better, and I have no back pain." We'll see what she says at age 50.