Vaping Cannabis Associated With More Respiratory Issues Than Vaping Tobacco, Study Finds

Teens who vape cannabis are almost twice as likely to report problems with wheezing and coughing than teens who smoke cigarettes or vape nicotine products, a new study has found.

Published in the Journal of Adolescent Health by researchers from the University of Michigan School of Nursing, the study looked at data gathered from nearly 15,000 students aged 12-to-17, collected as part of the national Population Assessment of Tobacco and Health (PATH) study.

They found that students who reported any lifetime use of cannabis vapes were at a greater risk than other groups for reporting symptoms of pulmonary irritation, including wheezing after exercise, wheezing that disrupts speech, and a nighttime dry cough.

The researchers say this study is the first of its kind to use recent PATH data – meaning that it will account for the rising popularity of e-cigarette products such as JUULs – while also accounting for asthma diagnoses in the students surveyed.

Teens vaping cannabis report greater likelihood of five respiratory concerns

Using binary logistic regression models adjusted to control for demographic factors, such as past asthma diagnoses, the researchers looked for any associations between past 30-day cigarette, e-cigarette, cannabis, or lifetime cannabis vape use and five symptoms of respiratory irritation.

Teens reporting any lifetime cannabis vape use were twice as likely to experience wheezing that limited their speech and almost twice as likely to report general wheezing, whistling in the chest, and sleep disturbances due to this wheezing. This group was also slightly more likely to report wheezing during or after exercise and a dry cough at night.

“I thought that e-cigarettes (vaping nicotine) would be the nicotine product most strongly associated with worrisome respiratory symptoms,” Dr Carol Boyd, the study’s principal investigator and a professor at the University of Michigan School of Nursing, said in a statement.

“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."

A past asthma diagnosis was still the most associated factor with these symptoms – teens with such a diagnosis were up to nine times more likely to report these symptoms. But the increased odds seen with lifetime cannabis vape use would suggest that cannabis vaping might present some unique negative health effects that warrant further investigation.

“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 said. “Without a doubt, cigarettes and e-cigarettes are unhealthy and not good for lungs. However, vaping marijuana appears even worse.”

Study limitations

There are several limitations on this study that are worth keeping in mind. Firstly, the use of pre-existing databases meant that there were limitations on exactly what data could be studied. For example, while there were data on past-30 day use for cigarettes, e-cigarettes, and any cannabis use, there were no discrete 30-day figures for cannabis vape usage alone. As a result, the researchers included data for any lifetime cannabis vape use, which they recognized maked “it more difficult to assess the longitudinal pattern[s]” related to current use.

This study also did not study the effects of using cannabis and tobacco products concurrently. Past studies into vape-related lung injuries have noted that co-use of both substances can promote or exacerbate symptoms of respiratory distress.

“Future studies need to assess if it is the combination of vaping both nicotine and cannabis that is creating so many respiratory issues,” said co-author Dr Philip Veliz, an assistant research professor of nursing at U-M. “It may be the combination of vaping cannabis along with smoking cigarettes is what leads to the high rates of respiratory symptoms among youthful marijuana vapers."

The researchers are very careful to stress that while cannabis vaping was associated with a greater number of reports of respiratory symptoms here, that does not mean that smoking cigarettes/e-cigarettes or cannabis products is perfectly safe – these products can also harm the lungs, just to a lesser degree in regard to the five symptoms specifically studied here.

It was not a part of the scope of the study to assess the effects of longer-term use or to look at the other possible health effects related to smoking, such as the build-up of tar in the lungs or lung cancer risk.

Cannabis vaping and EVALI

The safety of cannabis vaping became a public health concern following the outbreak of e-cigarette or vaping-related lung injuries (EVALI) across the US in 2019. These vaping-related injuries were seen far more often in people using cannabis vapes, eventually culminating in a consumer warning from the US Food and Drug Administration that told consumers to avoid all THC-containing vape products for their own safety.

As time passed and the number of these EVALI cases began to fall, the US Centers for Disease Control and Prevention (CDC) concluded that the likely culprit behind the injuries was vitamin E acetate – a diluent thickener seen more commonly in illicit cannabis vape products than in other sources.

Since the peak of EVALI cases in late-2019, additional research has also uncovered possible links between metallic heating elements and EVALI symptoms and the existence of a THC/vitamin E acetate complex whose health effects are unknown.

Given all of this, there is a push from within the cannabis industry to continue research into the safety of cannabis vape products to make sure that consumers are being as completely protected from health risks as possible.

“I think vaping is a great delivery system,” Dr Graham Wood, chief scientific officer at the extraction company Neptune Wellness Solutions, told Analytical Cannabis at the height of the vaping crisis. “It’s quite easy for consumers to control their dosing levels versus some of the edibles. Vaping gets rid of those issues.”

“But just because it’s better for giving that fine control, it still has to be as safe. So, I think we need to make sure that we're really paying attention to what's going in there. And as clinical studies continue, we're making it safer and safer as time goes on.”