Tobacco use in movies dropped sharply between 2005 and 2010, and this may have contributed to a decline in smoking rates among U.S. teens, according to a new study.

 

55% of movies with box office success in 2010 had no scenes that included tobacco use, compared with a third of the top-grossing films in 2005, according to the Centers for Disease Control and Prevention.

During the same six-year period, the number of what are called "tobacco incidents" in top-grossing movies fell by 56 percent, though there were still around 2,000 scenes where an actor used tobacco either openly, on screen, or implicitly, off-screen, according to the study.

"The percentages of 2010 top-grossing movies with no tobacco incidents were the highest observed in two decades," the CDC reported in the study.

"The decreased presence of onscreen smoking might have contributed to the decline in cigarette use among middle school and high school students," it noted.

That drop was discovered by a study released last year by the CDC that found that the percentage of middle school students in the United States who smoked cigarettes had declined six percent between 2000 and 2009, while the percent of those who "experimented" with cigarettes fell from nearly 30 percent to 15 percent.

Use of other tobacco products, such as cigars, pipes and chewing tobacco also dropped.