FRIDAY, April 29 (HealthDay News) -- Young teens who are allowed to drink alcohol under adult supervision don't learn about responsible drinking and actually drink more as they get older, a new study says.

Some parents believe that supervising their teens while they drink small amounts of alcohol will teach them to drink responsibly, according to the authors of the study published in the May issue of the Journal of Studies on Alcohol and Drugs.

Researchers followed more than 1,900 teens in Washington state and Victoria, Australia, as they progressed from seventh to ninth grade. The children were asked about their alcohol use, alcohol-related problems, and how often they drank alcohol with an adult present.

By eighth grade, about 67 percent of the Australian teens and 35 percent of the American teens had drunk alcohol with an adult present, a difference that reflects general cultural attitudes in the two countries. By ninth grade, 36 percent of Australian teens and 21 percent of American teens had experienced alcohol-related consequences such as not being able to stop drinking, having blackouts and getting into fights, the study found.

Teens in both countries who were allowed to drink under adult supervision had higher levels of alcohol use and were more likely to have experienced alcohol-related consequences by ninth grade.

The findings suggest that parents should not permit young teens to drink any alcohol, even under adult supervision, the researchers said.

"Kids need parents to be parents and not drinking buddies," lead researcher Barbara J. McMorris, of the University of Minnesota School of Nursing, said in a journal news release. "Adults need to be clear about what messages they are sending."

More information

The U.S. National Institute on Alcohol Abuse and Alcoholism has more about underage drinking.