Smoking Marijuana May Be Worse for Lungs Than Smoking Cigarettes

Airway irritation and emphysema are extra frequent in marijuana people who smoke than cigarette people who smoke, in accordance with new analysis.

Emphysema More Common in Marijuana Smokers Than Cigarette Smokers

According to new analysis, airway irritation and emphysema are extra frequent in marijuana people who smoke than cigarette people who smoke. Investigators mentioned the distinction could also be because of the method that marijuana is smoked and the truth that marijuana smoke enters the lungs unfiltered. The analysis examine was revealed on November 15 in Radiology, a journal of the Radiological Society of North America (RSNA).

Marijuana is the most-commonly smoked substance after tobacco and some of the broadly used psychoactive substances on the earth. Amid the legalization of leisure marijuana in Canada and lots of states within the U.S., its use has elevated considerably in recent times. With the rising use, there may be an pressing want for data on marijuana’s results on the lungs, one thing that’s presently missing.

“We know what cigarettes do to the lungs,” mentioned examine writer Giselle Revah, M.D., a cardiothoracic radiologist and assistant professor on the University of Ottawa in Ottawa, Canada. “There are well-researched and established findings of cigarette smoking on the lungs. Marijuana we know very little about.”

To discover out extra, Dr. Revah and colleagues in contrast chest CT outcomes from 56 marijuana people who smoke with these of 57 non-smoking controls and 33 tobacco-only people who smoke.

Three-quarters of the marijuana people who smoke had emphysema, a lung illness that causes issue with respiration, in contrast with 67% of the tobacco-only people who smoke. Only 5% of the non-smokers had emphysema. Paraseptal emphysema, which damages the tiny ducts that hook up with the air sacs within the lungs, was the predominant emphysema subtype in marijuana people who smoke in comparison with the tobacco-only group.

Airway adjustments in a 66-year-old male marijuana and tobacco smoker. Contrast-enhanced (A) axial and (B) coronal CT photos present cylindrical bronchiectasis and bronchial wall thickening (arrowheads) in a number of lung lobes bilaterally in a background of paraseptal (arrows) and centrilobular emphysema. Credit: Radiological Society of North America

Airway irritation was additionally extra frequent in marijuana people who smoke than non-smokers and tobacco-only people who smoke. The similar was true for gynecomastia, a situation of enlarged male breast tissue resulting from a hormone imbalance. Gynecomastia was present in 38% of the marijuana people who smoke, in contrast with simply 11% of the tobacco-only people who smoke and 16% of the controls.

The researchers discovered comparable outcomes amongst age-matched subgroups, the place the charges of emphysema and airway irritation had been once more increased within the marijuana people who smoke than the tobacco-only people who smoke.

There was no distinction in coronary artery calcification between age-matched marijuana and tobacco-only teams.

According to Dr. Revah, the outcomes had been stunning, particularly contemplating that the sufferers within the tobacco-only group had an intensive smoking historical past.

Pulmonary emphysema in (A, B) marijuana and (C, D) tobacco people who smoke. (A) Axial and (B) coronal CT photos in a 44-year-old male marijuana smoker present paraseptal emphysema (arrowheads) in bilateral higher lobes. (C) Axial and (D) coronal CT photos in a 66-year-old feminine tobacco smoker with centrilobular emphysema represented by areas of centrilobular lucency (arrowheads). Credit: Radiological Society of North America

“The fact that our marijuana smokers—some of whom also smoked tobacco—had additional findings of airway inflammation/chronic bronchitis suggests that marijuana has additional synergistic effects on the lungs above tobacco,” she mentioned. “In addition, our results were still significant when we compared the non-age-matched groups, including younger patients who smoked marijuana and who presumably had less lifetime exposure to cigarette smoke.”

There are doubtless a number of components that contribute to the variations between the 2 teams. Marijuana is smoked unfiltered, Dr. Revah famous, whereas tobacco cigarettes are normally filtered. This leads to extra particulates reaching the airways from smoking marijuana.

In addition, marijuana is inhaled with an extended breath maintain and puff quantity than tobacco smoke.

“It has been suggested that smoking a marijuana joint deposits four times more particulates in the lung than an average tobacco cigarette,” Dr. Revah mentioned. “These particulates are likely airway irritants.”

The increased incidence of emphysema may additionally be because of the method that marijuana is smoked. Full inhalation with a sustained Valsalva maneuver, an try at exhalation in opposition to a closed airway, might result in trauma and peripheral airspace adjustments.

More analysis is required, Dr. Revah mentioned, with bigger teams of individuals and extra knowledge on how a lot and the way typically individuals are smoking. Future analysis may additionally take a look at the impression of various inhalation methods, similar to by means of a bong, a joint, or a pipe.

“It would be interesting to see if the inhalation method makes a difference,” Dr. Revah mentioned.

For extra on this analysis, see Emphysema More Common in Marijuana Smokers Than Cigarette Smokers.

Reference: “Chest CT Findings in Marijuana Smokers” by Luke Murtha, Paul Sathiadoss, Jean-Paul Salameh, Matthew D. F. Mcinnes and Giselle Revah, 15 November 2022, Radiology.
DOI: 10.1148/radiol.212611