Vaping Cannabis Riskier Than Nicotine for Teens

University of Michigan study finds the odds of respiratory symptoms were about twice as likely among marijuana vapers as smokers.

April 05, 2021

ANN ARBOR, Mich.—New research from the University of Michigan indicates that vaping cannabis raises the risk of teens developing lung injuries more than smoking cigarettes or marijuana or vaping nicotine. The findings challenge assumptions that vaping nicotine is more harmful to the lungs, Michigan Health Lab reports.

Researchers examined self-reported respiratory symptoms from teens 12 to 17 years old who participated in the 2016-18 Wave of the Population Assessment of Tobacco and Health Study. Symptoms included wheezing, sleep disturbances or limited speech due to wheezing, wheezing after exercise and a nighttime dry cough not related to a chest illness or infection.

Teens who self-reported vaping cannabis were about twice as likely to report “wheezing or whistling” in the chest as teens who didn’t report vaping marijuana. Use of e-cigarettes, cigarettes and cannabis also were associated with dry cough and other respiratory symptoms, but most of the associations weren’t significant after controlling for vaping cannabis, the study found.

The minimum U.S. age to purchase tobacco products is 21. Although many states have legalized cannabis for recreational use by adults, the threshold is set at age 21, and cannabis remains illegal at the federal level.

“I thought that e-cigarettes [vaping nicotine] would be the nicotine product most strongly associated with worrisome respiratory symptoms,” said Carol Boyd, Ph.D., the study’s principal author and the Deborah J. Oakley Collegiate Professor Emerita at the University of Michigan School of Nursing.

“Our data challenges the assumption that smoking cigarettes or vaping nicotine is the most harmful to the lungs. If we control for vaping cannabis in our analyses, we find there is a weaker relationship between e-cigarette or cigarette use and respiratory symptoms when compared to vaping cannabis,” Boyd said.

The findings, however, don’t mean that vaping nicotine or smoking cigarettes or cannabis aren’t without health risks. Symptoms of lung injury are also associated with use of these products, albeit not to the same degree as vaping marijuana, Boyd said.

“In short, it is all bad, but if you also vape cannabis you have a greater number of unhealthy respiratory symptoms than if you just smoke cigarettes or marijuana, or vape e-cigarettes,” Boyd told Michigan Health Lab. “Without a doubt, cigarettes and e-cigarettes are unhealthy and not good for lungs. However, vaping marijuana appears even worse.”

The researchers point out that a limitation of the study is that it didn’t examine co-use of vaping cannabis and e-cigarettes or combustible cigarettes.

The study, “Cannabis, Vaping, and Respiratory Symptoms in a Probability Sample of U.S. Youth,” appears in the Journal of Adolescent Health.