5. Keira Knightley

Even though she recently turned 30, actress Keira Knightley still looks like she’s in her twenties and it’s something many women envy her for.

However, if she continues her habit of heavy smoking, she might just turn from babe to hag in a matter of years.

The star of “Pirates of the Caribbean” is a true monument of commitment when it comes to cigarettes. She had a close encounter with anorexia in the past and her profession demands her appearance to be intact, but she still keeps puffing away.

Some even believe that Knightley is using smoking as a way to prevent weight gain, but as far as we can tell, that’s all just hearsay.