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Comparative Analysis of Respiratory Effects: Marijuana Versus Tobacco

Dr. Craig Smith, MD

4 Min read

In a recent study published in Radiology, a journal of the Radiological Society of North America, researchers delved into the intricate relationship between marijuana and tobacco use and their respective impacts on lung health. The findings shed light on potential disparities in the prevalence of lung diseases, emphasizing the need for a more nuanced understanding of the respiratory effects associated with these commonly used substances.

Marijuana, now legal for recreational use in several U.S. states and Canada, has long been a subject of scientific inquiry. The study's lead author, Dr. Giselle Revah, a cardiothoracic radiologist and assistant professor at the University of Ottawa in Canada, highlighted the knowledge gap surrounding the effects of marijuana on the lungs. While the detrimental impact of cigarette smoking is well-documented, marijuana's influence remains less explored.

The research compared chest CT scans from three groups: 56 marijuana smokers, 57 non-smokers, and 33 tobacco-only smokers. Strikingly, 75% of marijuana smokers exhibited emphysema, a condition characterized by breathing difficulties, compared to 67% of tobacco-only smokers. In contrast, only 5% of non-smokers displayed signs of emphysema. The predominant subtype of emphysema observed in marijuana smokers was paraseptal emphysema, which damages tiny ducts connected to the air sacs in the lungs.

Airway inflammation emerged as another notable distinction between marijuana and tobacco smokers. Marijuana smokers displayed higher rates of airway inflammation compared to both non-smokers and tobacco-only smokers. Additionally, the study identified an association between marijuana use and gynecomastia, the enlargement of male breast tissue due to a hormone imbalance. Gynecomastia was found in 38% of marijuana smokers, 11% of tobacco-only smokers, and 16% of non-smokers.

Notably, the study encompassed various age groups, affirming that marijuana smokers consistently exhibited higher rates of emphysema and airway inflammation compared to their tobacco-using counterparts. However, there was no significant difference in coronary artery calcification between age-matched marijuana and tobacco-only groups.

To further understand these findings, Healthline sought insights from Dr. Shahryar Yadegar, a pulmonologist and medical director at the ICU at Providence Cedars-Sinai Tarzana Medical Center in California. Dr. Yadegar emphasized the role of particulate matter inhalation in causing inflammation within the airways, common to both marijuana and tobacco smoke. He highlighted the variability in additives, including flavors, preservatives, and pesticides, between cannabis and tobacco products.

Jordyn Mastrodomenico, the clinical director at ChoicePoint, a New Jersey-based addiction treatment center, added a layer of complexity to the discussion. Mastrodomenico highlighted that the damage to the lungs from marijuana stems from the way it is smoked. Deeper inhalation and prolonged breath-holding expose the alveoli, the small air sacs in the lungs, to irritants for an extended period. Moreover, marijuana smoke contains a higher concentration of carcinogens compared to tobacco, contributing to increased tar deposition in the lungs.

The study's results took the researchers by surprise, particularly considering the extensive smoking history of individuals in the tobacco-only group. Dr. Revah expressed astonishment at the additional findings of airway inflammation and chronic bronchitis among marijuana smokers, even when accounting for those who also smoked tobacco. This suggests potential synergistic effects of marijuana on the lungs beyond those associated with tobacco use.

Dr. Revah stressed the need for further research, calling for larger sample sizes and more comprehensive data on smoking habits. Exploring the impact of different inhalation techniques, such as using a bong, a joint, or a pipe, could provide valuable insights into mitigating potential risks associated with marijuana use.

In conclusion, as the landscape of marijuana use evolves with increasing legalization, understanding its impact on lung health becomes paramount. The study underscores the intricate relationship between marijuana smoke and respiratory health, urging for continued research to inform public health initiatives and promote informed decision-making regarding the use of these substances.

About the Author

In 1984, Dr. Craig Smith founded Lifesource. As a coach, he's worked with world-class athletes and guided thousands towards successful weight loss. Driven by a desire to elevate his understanding of the human body, he returned to the rigors of medical school in his 50s, achieving his goal of becoming a physician at 56. Now in his 60s, Dr. Smith leads by personal example, continuing to inspire, educate and empower individuals from all walks of life to achieve their health and fitness goals. If you wish to train and diet online with Dr. Smith, hear his message and schedule a 45-minute consultation on the New You page.