- A study found higher rates of emphysema in marijuana smokers compared to tobacco smokers of the same age.
- The study author told Insider that his research raises concerns that smoking marijuana is no safer than cigarettes.
- The results suggest that smoking both marijuana and cigarettes is more harmful than smoking tobacco per se.
A small study found higher rates of emphysemaa lung condition that causes shortness of breath, among marijuana smokers compared to tobacco smokers of the same age. The study also suggests that using marijuana and tobacco together may be more harmful than using tobacco on its own.
Dr. Giselle Revahcardiothoracic radiologist at The Ottawa Hospital and lead author of the study, reviewed chest CT scans at The Ottawa Hospital from 2005 to 2020 and identified 56 patients who reported using marijuana.
The majority of marijuana users – 50 of 56 patients – said they also smoked cigarettes. She compared them to 33 tobacco-only smokers and 57 non-smokers.
The age of tobacco-only smokers was higher because Revah collected these chest CT scans from patients through his hospital’s department. lung cancer screening event, which was open to patients over 50 who self-identified as heavy smokers. Marijuana smokers in his sample tended to undergo chest CT scans for reasons unrelated to emphysema.
When the radiologist compared tobacco smokers only to marijuana smokers of the same age, the marijuana smokers had higher rates of emphysema: 93% (28 of 30) versus 67% of the tobacco smokers of the same age.
The radiologist found that marijuana users overall – including younger people who hadn’t been exposed to as much smoke – had significantly higher rates, particularly of paraseptal emphysema, a rare form of the disease which damages the tiny ducts that connect the air sacs of the lungs.
The way marijuana smokers use the drug can damage the air sacs. Marijuana users tend to breathe deeply and hold smoke longer, causing pressure changes that can irritate the air sacs in the lungs, Revah told Insider.
“The main message of the whole study is that there’s this public perception that marijuana is safe; people believe it’s safer than cigarettes,” Revah said. “And this study raises concerns that marijuana may not be as safe as everyone thinks, and suggests that ultimately we need more robust research before we can draw any conclusions. radical conclusions.
The paper sheds light on the understudied health effects of marijuana. Literature on chest scans of marijuana smokers is sparse, Revah said, since Canada only legalized the drug in 2018. The United States has not legalized cannabis nationwide, and getting funding for marijuana research involves heavy legal procedures.
Pulmonary doctors told Insider that more research is needed on the health effects of marijuana use.
Dr Philippe Diaz, a lung disease physician at Ohio State University Wexner Medical Center who was not involved in the study, said that since most of the marijuana smokers in the study were cigarette smokers , smoking both marijuana and cigarettes may increase the risk of lung damage. But Diaz stressed that the results of the small study should not be overstated.
“You don’t want to dilute the fact that smoking is really the problem,” Diaz told Insider. “I think all you could say is there could be an increased risk if you do both.”
Revah said she is working on a prospective study that asks patients how much marijuana they use and hopes a larger study will confirm her findings.
Dr. Albert Rizzothe chief medical officer of the American Lung Association, told Insider that scientists and doctors need longer, more in-depth studies on the long-term health effects of marijuana, especially since the drug is quickly becomes legal in the states of the United States.
“I think this study is good for trying to show or support that using marijuana in the airways leads to problems, emphysema being one of them,” Rizzo told Insider. “Smoking marijuana is not safe, and we don’t really know what the long-term effect of smoking marijuana is.”