THURSDAY, Aug. 21 (HealthDay News) -- Mass media has the power to both encourage tobacco use, especially among young people, and to discourage it, according to a landmark study released Thursday by the U.S. National Cancer Institute.

"This is the first report to conclude that tobacco advertising and promotion increases tobacco use," said Melanie Wakefield, senior scientific editor of the report, The Role of the Media in Promoting and Reducing Tobacco Use.

"It's the first report to make the conclusion that there is a causal relationship between exposure to depiction of smoking in the movies and youth beginning to smoke," she said.

The findings in the hefty, nearly 700-page report aren't all bad about media and its effects on tobacco use, however.

"Mass media can change youth attitudes about tobacco use," Wakefield said. Mass media campaigns to discourage tobacco use have proven to change youth attitudes about tobacco, reduce the chances children will smoke, and encourage adult cessation, the authors said during a press conference in Washington, D.C.

The report, which took four years to compile, involved expert analysis from 23 authors as well as input from numerous other experts, Wakefield said. They analyzed more than 1,000 scientific studies on the role of media in encouraging and discouraging tobacco use. The report reached several major conclusions, including:

• Media play a key role in shaping knowledge, opinions, attitudes and behaviors among people and within communities. "Cigarettes are one of the most heavily marketed products in the United States," the authors wrote. Tobacco manufacturers in the United States spent about $250 billion (in 2006 dollars) between 1940 and 2005 on cigarette advertising and promotion. Most of this, the authors found, was allocated to promotional activities, such as price discounts, which are particularly attractive to youth.
• The tobacco industry lures smokers with three themes: That tobacco provides satisfaction, that the dangers of tobacco shouldn't provoke anxiety, and that tobacco is associated with desirable outcomes such as social success.
• A causal relationship exists between tobacco promotion and ads and increased tobacco use.
• Depiction of smoking is still pervasive in movies. It occurs in three-quarters or more of contemporary box-office hits. This exposure leads to more youth smoking.
• On the positive side, media campaigns meant to reduce tobacco use do work, helping to change youth attitudes about tobacco, thereby reducing the chances children will start smoking.

The authors noted a nationwide decline in smoking -- about a 50 percent drop in adult smoking over the past 40 years -- but pointed out that one in five Americans still smokes, and more than 4,000 children and teens smoke their first cigarette each day.

Citing statistics from the U.S. Centers for Disease Control and Prevention, the report authors said cigarette smoking is responsible for more than 400,000 premature deaths each year, and reduces the life expectancy of smokers by an average of 14 years.

"The report stops at synthesizing the evidence," Wakefield said. "Now it is up to the government to consider the evidence and think about what it needs to do in terms of advertising and promotion."

While the report was released by the U.S. National Cancer Institute, "other nations will take note of this report," she said.

William Corr, executive director of the Campaign for Tobacco-Free Kids, who also spoke at the press conference, said: "This report sends an unmistakable message to our elected officials that they can dramatically reduce tobacco use by children and by adults by passing legislation that would authorize the Food and Drug Administration to regulate tobacco products and by adequately funding their state prevention and cessation programs."

Bill Phelps, a spokesman for the Altria Group, the parent company of Philip Morris USA, took issue with some of the findings. "It appears that many of the conclusions in the report are based on marketing practices that are more than 30 or 40 years old," he said. "We think it's important to focus on the marketing practices that we have in place today."

He said that spending for cigarette brand advertising for Philip Morris USA, which includes Marlboro cigarettes, has dropped 46 percent in the past 10 years. Philip Morris supports federal legislation under consideration to regulate tobacco products, he said.

In July, the U.S. House of Representatives passed legislation that would subject the tobacco industry to federal regulation, including granting the FDA the power to regulate tobacco products. The Senate has yet to act on a similar measure.

More information

For more on keeping kids free from tobacco, visit the Campaign for Tobacco-Free Kids.