Minnesota communities that set 21 as the minimum age to buy tobacco products saw lower rates of tobacco use among eighth- and ninth-graders, according to a study done by University of Minnesota and Minnesota Department of Health researchers.

About five years ago, some cities and counties raised the tobacco purchase age from 18 to 21 at a time when vaping was impeding progress on tobacco reduction efforts.

A survey of Minnesota high school students in 2017 found that tobacco use had increased to 26.4% from 24.6% in 2014. It was the first increase the survey had detected since the state's Minnesota Youth Tobacco Survey began in 2000.

Edina became the first city to raise the purchase age in 2017. By mid-2019, 28 other localities implemented similar policies.

"The majority of young people start using tobacco products under the age of 21 so if we can cut off the supply and limit access we can reduce use," said Dr. April Wilhelm, a family medicine physician with the U Medical School and M Health Fairview and lead author of the study.

The research team compared tobacco use rates among students in communities that raised the purchasing age with those that didn't.

Using results from the Minnesota Student Survey, researchers found that the odds of tobacco use among eighth- and ninth-graders in communities with higher purchase ages were significantly lower from 2016 to 2019.

"What this suggests is that this policy might be contributing to some of the reduction in tobacco use," Wilhelm said.

But the researchers did not detect a measurable difference among 11th-graders.

"We were a bit surprised that there was such a dramatic difference in the 11th-grade group," said Wilhelm. "It is possible that there is a benefit, but we just didn't detect it."

Last year, the Legislature raised the tobacco purchase age to 21 statewide, mirroring a federal law passed in 2019.

In the most recent Minnesota Youth Tobacco Survey, use of tobacco products declined in 2020, with 20.5% of high schoolers reporting use in the past 30 days and 4.1% of middle schoolers.

Use of electronic cigarettes among high schoolers has risen since they were first asked about them by the survey in 2014, going from about 15 to 19.3% in 2020.

Glenn Howatt • 612-673-7192

Twitter: @GlennHowatt