Parents, take heed

When should you talk to your kids about alcohol? Before they turn 10, doctors say

Adolescence is a time marked by testing limits and exploring the unexplored, the authors of Monday's study note.

"It is no coincidence that this is the chief period for initiating substance use," they said. "Alcohol is the substance most frequently used by children and adolescents in the United States, and its use in youth is associated with the leading causes of death and serious injury at this age (i.e., motor vehicle accidents, homicides, and suicides)."

Researchers found that 21 percent of young people have tried more than a sip of alcohol by age 13, and nearly 80 percent acknowledged drinking before graduating high school.

In addition, the study noted, 4 out of 5 teenagers said their parents had the biggest influence over when — and whether — they decided to drink. A 2013 study, for example, found that parental communication about alcohol before college helped prevent students who didn't drink from becoming heavy drinkers. It also greatly reduced drinking patterns among teenagers who already had begun drinking prior to college.