Media literate teens are half as likely to take up smoking than their peers who have less understanding of advertising methods and motives, suggests a new study.

"Many factors that influence a teen’s decision to smoke — like peer influence, parental smoking and risk-seeking tendency — are difficult to change," Brian Primack, an assistant professor at the University of Pittsburgh and the study’s lead author, said in a release.

"However, media literacy, which can be taught, may be a valuable tool in efforts to discourage teens from smoking."

The study, published in the current issue of the Journal of Adolescent Health, surveyed 1,200 Pittsburgh high school students to determine their level of media literacy. Students were asked to rate statements such as "Advertisements usually leave out a lot of important information," and "Movie scenes with smoking in them are made very carefully."

Researchers said that since students with scores above the median were half as likely to smoke, anti-smoking campaigns should be focused differently. Media literacy training could prove more effective than negative warning messages, the study said.

"Acknowledging the effects of media on attitudes and behaviour, media literacy teaches youth to understand, analyze, and evaluate advertising and other media messages, enabling them to actively process media messages rather than passively remain message targets," the study said.

Statistics Canada data has shown that smoking in Canada has decreased, especially among teens. In 2001, 73 per cent of youth said they never smoked cigarettes while in 2005, the percentage was 82 per cent.

In 1997, the federal government enacted the Tobacco Act to regulate the sale, manufacturing and promotion of cigarettes. The act includes stipulations that tobacco companies cannot promote their products by associating them with glamour, recreation, excitement, vitality, risk, daring or sexuality.

The study noted that developing a more comprehensive understanding of advertisements and media motives may also influence other behaviours including eating, aggression and alcohol use. Researchers said that youth are swamped with negative messages in the media.

"Although it is important to continue to attempt to reduce the amount of exposure to potentially harmful media messages during adolescence, it is not always feasible to do so," the study said. "Media literacy may therefore be a practical and empowering co-intervention."