(CBS) It's not unusual to see a movie with characters who drink or get drunk. It's also no secret that many booze-heavy movies are geared toward a younger audience.
But a new study confirms some parents' biggest fears. It found teens who watch lots of movies featuring alcohol are twice as likely to drink than their peers who avoid such films.
"Like influenza, images in Hollywood movies begin in one region of the world then spread globally, where they may affect drinking behaviors of adolescents everywhere they are distributed," the study authors wrote.
For the study, published online in the Feb. 20 issue of British Medical Journal Open, researchers surveyed 6,500 U.S. teens between ages 10 and 14 years, starting in 2003. The researchers gave the teens a list of the top 100 U.S. box office hits in each of the preceding 5 years plus the 32 top-grossing films of 2003, and asked teens which ones they'd seen. The researchers tracked the length of alcohol scenes in all 532 movies, and based on the responses, determined teens saw an average of four-plus hours of on-screen alcohol use. But some teens in the study saw well over eight hours of these scenes.
Over the course of the two-year survey period, researchers found teens who watched the most movies featuring alcohol were twice as likely to start drinking as those who watched the least. Those teens were also 63 percent more likely to progress to binge drinking. And it's not like these were the types of teens who sneak into R movies.
"It's really not incorporated into the ratings at all," study author Dr. James Sargent, professor of pediatrics at Darmouth, told NPR. "There's just as much in PG-13 movies as there is in R movies."
The study did not determine cause and effect, only an association between watching the movies and drinking. Other factors such as whether their parents drank, peer behavior, and whether the teens owned alcohol merchandise were considered. The association was seen not only if the movie characters drink, but also with alcohol product placement, the authors said. They're calling on Hollywood execs to adopt stricter regulations on alcohol placement in movies, just as they do for tobacco
Sargent tells NPR that parents can limit this exposure by just limiting how much time teens spend watching movies in general. But if the family is sitting around watching a movie and alcohol pops up on screen, have a discussion.
"A lot of families sit around and watch movies together, but it's uncommon for them to discuss things," Sargent says. "You want to teach them to be skeptical of what they see."
If ais any indication, some of these teens may grow up to drink more. A 2012 study found 38 million U.S. adults binge drink, and college-age Americans were found to drink an average of nine drinks when they bing. Binge drinking can lead to 54 health risks, the CDC says, including liver disease, injuries, car crashes, and sexually transmitted diseases.
The CDC has more on teen drinking.