If it hadn't already sunk in that smoking was a harmful habit (read: cancer, wrinkles, bad breath, etc.), maybe this little discovery will convince smokers to finally get off their butts. According to a new report presented at the conference of the American Society of Plastic Surgeons, smoking has a bigger impact on breast sagginess than breastfeeding.

As Live Science reports, University of Kentucky plastic surgeon Brian Rinker and his colleagues conducted a study to determine what role breastfeeding - a common excuse for droopy breasts - played in reducing breast elasticity. The team questioned 132 women who had undergone breast lifts or augmentation from 1998 to 2006, gathering information on their medical history, smoking habits, body mass index, and bra sizes before pregnancy.

Of the women, 93% (average age: 39) were mothers, and 58% of those had breast-fed at least one of their children. But when compared to women who had not breast-fed, there was no difference in the amount of breast sagging.

The factors that did impact the breast were smoking, age, and the number of pregnancies a woman had experienced.

"Smoking breaks down a protein in the skin called elastin, which gives youthful skin its elastic appearance and supports the breast," Rinker says. He also noted that pregnancy was a strong contributor to breast ptosis, with sagginess increasing with each pregnancy.

On the bright side, new mothers can breast-feed without the fear of creating more damage. But you may want to hold off on that second kid - and that pack of smokes.