MONDAY, Feb. 23 (HealthDay News) -- Children who are allowed to watch R-rated movies are more likely to smoke, say researchers who analyzed data from a four-year study of more than 1,200 Massachusetts youngsters.

"We don't know why this is so. It may have to do with a parenting style that is permissive of activities that are not age-appropriate. Or it may be an outcome of all the smoking scenes in R-rated movies," lead author Chyke Doubeni and colleagues at the University of Massachusetts Medical School said in a news release.

The participants were in the sixth grade when the study started in 2002 and were interviewed 11 times between then and 2006. The students were asked a number of questions about their access to cigarettes, whether smoking was allowed in their home and whether they were allowed to watch R-rated movies and videos.

Among those who were allowed to watch R-rated movies, smokers were nearly three times as likely and nonsmokers were almost twice as likely to say it would be easy for them to get cigarettes, compared to youngsters who weren't allowed to watch R-rated movies.

The findings are published in the Feb. 21 issue of the American Journal of Preventive Medicine.

According to Doubeni, the study shows that parental permission to watch R-rated movies is one of the strongest predictors of children's belief that cigarettes are easily available, about as strong as having friends that smoke.

"We do know that kids who believe it is easy to get a cigarette are at risk of smoking," Doubeni said. "Our prior research has already shown that kids who perceive cigarettes as readily accessible are more likely to end up as regular smokers."

"Parents need to be mindful about the movies their children watch for a variety of obvious reasons," added co-author Dr. Joseph DiFranza. "This study points out one more reason for not allowing children to watch movies that are not appropriate for their age.

• More News on Smoking and Youth

Related MedlinePlus Pages:

• Smoking and Youth