Teenagers who watch more alcohol advertising may drink more and tend to prefer the brands they’ve seen on television, a new study suggests.

The study — conducted by researchers at the Boston University School of Public Health and published in the September issue of Journal of Studies — was announced publicly Wednesday and suggests that teenagers who saw more advertisements for a particular brand of alcoholic beverage were likely to buy more of it. The study was also able to find a correlation between the number of ads for alcoholic beverages teens were exposed to and how much booze they consumed in any given month.

“This could be yet another reason to limit screen time,” Timothy Naimi, the lead author of the study and an associate professor of community health services at BU, said.

The number of ads seen significantly altered how much an underage drinker consumed during any given month. Measuring the amount of exposure to the ads in “adstock units,” the researchers found that a teenager who didn’t see any ads would have about 14 drinks a month. That number rises to 30 drinks a month if they’d seen 300 adstock units. Increased exposure to adstock units could put the number of drinks a month at 200 or more.

Advertising for alcohol is largely a self-regulated affair. There are guidelines urging advertisers to only put the ads on shows that attract mostly adult audiences, but there are also no penalties for any violations, Eureka Alert! reported.

It can be difficult to know exactly how many teens are hitting the bottle. In 2014, a study found that about three million 12 to 17 year olds voluntarily reported drinking during any given month. That number was shown to increase as the kids grew up. Only 10 percent of 12-year-olds were drinkers in that study but 70 percent of 18-year-olds said they’d tried alcohol.