A new study finds states that have more restrictive rules on youth access to tobacco also have lower rates of adult smoking.

Researchers at Washington University School of Medicine in St. Louis found states with more restrictions on youth access to tobacco also tend to have fewer adult heavy smokers, Newswise reports.

The study, published in the American Journal of Public Health, included data from a National Cancer Institute survey of smoking behavior. The researchers evaluated smoking behaviors of 105,519 people ages 18 to 34, and compared that information with the smoking restrictions in the states participants lived in when they were 17 years old.

Many states do not have provisions to prevent tobacco sales to minors, even though those sales are illegal, the study authors note. They found that in states that enforced laws governing youth access to tobacco, 17-year-olds had more difficulty buying cigarettes. When these individuals reached their 20s or 30s, they were less likely to smoke.

“We estimated that if all states had effective policies in place, it would reduce the prevalence of smoking by about 14 percent and the rates of heavy smoking by 29 percent,” study first author Richard A. Grucza noted in a news release. “This study shows that more restrictive policies can prevent teen smoking and be beneficial down the road.”

The researchers found the most effective restrictions included eliminating cigarette vending machines or placing them in locations inaccessible to those under 18; requiring identification for purchasing cigarettes; restricting the repackaging of cigarettes to prevent the sale of a few cigarettes at a time; and banning distribution of free cigarettes at public events.

Restricting youth access to tobacco was more effective in reducing smoking among women than among men, the study found.