As if parents don't already have enough to worry about, a study out Tuesday from the University of Minnesota School of Public Health says alcohol drinking prevention programs should be  addressed to students as young as third grade because by the sixth grade it's too late for the one-in-six who are already using alcohol.

Shocked? You're not alone.

"Parents and the general public don't realize how early alcohol use starts," said Keryn Pasch, first author of the study published online in the journal Health Education and Behavior.

The study compared 4,000 Chicago sixth-graders who had used alcohol in the past year to those who had not. Among this sample, 17 percent had used alcohol within the past year.

Other studies have also shown that some middle schoolers drink alcohol. The good news is that most students have no experience with alcohol, according to researcher John Donovan of the University of Pittsburgh. Last year Donovan published a paper that tabulated data from four U.S. surveys on children and alcohol from the 1990s until 2005.

But even sipping alcohol is more common than parents might think, according to a January study by Donovan. In that study, 39 percent of 452 8- and 10-year-olds had sipped or tasted alcohol in the last year. But only six percent had had a full drink. Most experiences happened at home, or during celebrations or religious services.

According to the university's Pasch, sixth-graders who drink alcohol — and we're not talking licking the foam off Dad's beer — tend to be boys who get into fights and hang out with others like themselves. Messages about the pitfalls of drinking alcohol don't work for those kids, she said. But they might work for kids before they reach that point.

The researcher's advice? The same as it used to be for teenagers.

Parents should talk with their kids about the negative effects of drinking alcohol and teach them how to deal with peer pressure, but in a way that 8-year-olds can understand.