MONDAY, Nov. 7, 2005 (HealthDay News) -- Teens are more likely to try smoking if they see their favorite movie stars light up on screen, according to the results of the largest study of its kind.
Even after researchers took into account factors such as friends and family members who smoke, adolescents who watched the most tobacco use on screen were 2.6 times more likely to experiment with smoking than those who watched the least.
It wasn't clear if the teens continued to smoke. Even so, "it looks like movies are responsible for about a third to 40 percent of (teen) smoking," said study author Dr. James Sargent, a professor of pediatrics at Dartmouth Medical School. "It's a pretty substantial share."
Previous studies, including one by Sargent, have shown a link between on-screen smoking and teen smoking. But other factors have been blamed for teen smoking, too, including tobacco advertising in convenience stores.
Most recently, a study released in the August issue of Chest raised questions about whether movies are really as smoke-filled as anti-smoking activists suggest. Researchers found that less than a quarter of movie characters smoked in a sampling of films from the 1990s, about equal to those in the U.S. population as a whole. And the most villainous characters -- not necessarily the most glamorous -- were most likely to light up.
The new study is the first to look at the relationship between movies and smoking in a national sample of teens. Researchers randomly surveyed 6,522 adolescents from ages 10 to 14, asking them about recent movies they'd seen and whether they'd tried smoking.
Those who acknowledged experimenting with smoking were more likely to have seen more incidents of smoking in movies. According to the study, smoking appeared in 74 percent of the 500 most popular movies from 1998 to 2002, and 32 popular movies from the first four months of 2003.
The connection between on-screen and real-life smoking held up even when the researchers adjusted statistics to account for the influence of other factors, such as friends and relatives who smoke, family income and academic performance, as well as race and gender.
"It doesn't matter where adolescents live, or what kinds of families they grow up in, they all tend to respond to seeing smoking in movies," Sargent said.
However, the study only suggests there's a link between movie smoking and teen smoking; it doesn't prove a cause-and-effect relationship.
Sargent acknowledged that fact, but said "there's still a really strong association." He also said the researchers went "further than many studies in controlling for all these other factors."
What's the message for Hollywood? Sargent doesn't mince words: "Anytime a director directs someone to light a cigarette, anytime an actor lights a cigarette, they should understand that they're partially responsible for the teen smoking epidemic."
Prominent anti-smoking activist Stanton A. Glantz, director of the Center for Tobacco Control Research at the University of California, San Francisco, went even further.
"If Hollywood just got the smoking out of youth-related films, it would have a huge effect, and it would cost nothing," Glantz said. "It would be the most cost-effective health intervention ever done."
For more on the need for smoke-fee movies, visit the University of California, San Francisco.