In the wake of research by the National Cancer Institute linking on-screen depictions of cigarette smoking with higher rates of smoking among young people, three major film studios have drastically reduced the frequency of cigarette-related images in their youth-oriented movies.

The Centers for Disease Control and Prevention released a study Thursday detailing smoking in top-grossing movies.  The Associated Press reports that over the past five years, scenes involving tobacco dropped from an average of 23 to one per film for those companies (a drop of 96 percent), and most of their youth movies had no smoking at all.

The three movie companies--Time Warner (Warner Bros.); Comcast (Universal and Focus Features); and the Walt Disney Company (Walt Disney Pictures, Touchstone, Pixar and Buena Vista)--all have official company policies aimed at reducing tobacco exposure on screen.  For companies that don't have similar policies, smoking still decreased by 42 percent in films, though more than 40 percent of the films still depicted tobacco use.