Cigarette smoking has long been recognized as a cause of emphysema and chronic obstructive pulmonary disease (COPD). It contains a variety of dangerous compounds, like as nicotine, tar, and carcinogens, which can cause lung tissue damage and inflammation.
According to a study published in Radiology, a journal of the Radiological Society of North America (RSNA), marijuana smokers have higher rates of airway inflammation and emphysema than cigarette smokers. According to the researchers, the discrepancy could be attributable to the method marijuana is smoked and the fact that marijuana smoke enters the lungs unfiltered.
Marijuana is one of the world’s most widely used psychoactive substances, and it is the second most regularly smoked substance after tobacco. Its popularity has grown in recent years as recreational marijuana has been legal in Canada and numerous states throughout the United States. Because of the increased use, there is an urgent need for information on marijuana’s effects on the lungs, which is currently lacking.
“We know what cigarettes do to the lungs,” said Dr. Giselle Revah, a cardiothoracic radiologist and assistant professor at the University of Ottawa in Ottawa, Canada. “The effects of cigarette smoking on the lungs have been well researched and established. We know very little about marijuana.”
We know what cigarettes do to the lungs. The effects of cigarette smoking on the lungs have been well-researched and established. We know very little about marijuana.
Dr. Giselle Revah
Dr. Revah and colleagues compared the chest CT results of 56 marijuana smokers to those of 57 nonsmokers and 33 tobacco-only smokers to learn more.
In comparison to 67% of tobacco smokers, three-quarters of marijuana smokers had emphysema, a lung disease that causes difficulty breathing. Only 5% of those who did not smoke had emphysema. When compared to the tobacco-only group, marijuana users had a higher prevalence of paraseptal emphysema, which affects the small ducts that connect to the air sacs in the lungs.
Airway inflammation was also more common in marijuana smokers than non-smokers and tobacco-only smokers, as was gynecomastia, enlarged male breast tissue due to a hormone imbalance. Gynecomastia was found in 38% of the marijuana smokers, compared with 11% of the tobacco-only smokers and 16% of the controls.
The researchers found similar results among age-matched subgroups, where the rates of emphysema and airway inflammation were again higher in the marijuana smokers than the tobacco-only smokers. There was no difference in coronary artery calcification between age-matched marijuana and tobacco-only groups.
Dr. Revah said the results were surprising, especially considering that the patients in the tobacco-only group had an extensive smoking history.
“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 explained. “In addition, when we compared the non-age-matched groups, including younger patients who smoked marijuana and presumably had less lifetime exposure to cigarette smoke, our results remained significant.”
The discrepancies between the two groups are most likely attributable to a combination of variables. According to Dr. Revah, marijuana is smoked unfiltered, whereas tobacco cigarettes are frequently filtered. As a result, more particles from marijuana smoke enter the lungs.
Furthermore, marijuana smoke is inhaled with a longer breath hold and a larger puff volume than tobacco smoke.
“It has been suggested that smoking a marijuana joint deposits four times more particulates in the lungs than smoking an average tobacco cigarette,” Dr. Revah explained. “These particulates are likely to be airway irritants.”
The increased prevalence of emphysema may possibly be linked to the manner in which marijuana is smoked. Full inhalation with a persistent Valsalva maneuver, as well as an attempt to exhale against a closed airway, can result in damage and alterations to the peripheral airways.
