Cannabis Smoke Affects Lungs Similarly to Tobacco With Some Additional Risks
A review found cannabis smoke causes symptoms similar to tobacco (cough, sputum, bronchitis) and may weaken immunity leading to pneumonia, with potential but inconclusive links to lung cancer with heavy, long-term use.
Quick Facts
What This Study Found
This review examined the pulmonary effects of cannabis smoking. Cannabis smoke affects the lungs similarly to tobacco smoke, producing symptoms of increased cough, sputum production, and airway hyperinflation.
With increasing years of use, cannabis can cause serious lung diseases. It can weaken the immune system in the lungs, leading to pneumonia. Regular use has been linked to symptoms of chronic bronchitis, and heavy long-term use on its own may cause airway obstruction.
Based on immunohistopathological and epidemiological evidence, the review concluded that cannabis poses a potential risk for lung cancer. However, the association was described as "not decisive," meaning the evidence was suggestive but not conclusive. The difficulty in separating cannabis effects from tobacco effects (since many users smoke both) was noted as a major methodological challenge.
Key Numbers
The review synthesized evidence from immunohistopathological and epidemiological studies. Specific rates were not quantified, but associations were described for bronchitis, pneumonia, airway obstruction, and potential lung cancer risk.
How They Did This
Narrative review examining immunohistopathological and epidemiological evidence on the respiratory effects of cannabis smoking, published as a chapter in Advances in Experimental Medicine and Biology.
Why This Research Matters
As cannabis use increases with legalization, understanding its respiratory effects independent of tobacco is important. This review provides a concise summary of the lung-related risks, which include bronchitis, immune suppression, airway obstruction, and a potential but unproven cancer risk.
The Bigger Picture
The respiratory effects of cannabis remain one of the most debated areas of cannabis research. While some studies show increased lung capacity (paradoxically), this review emphasizes the harmful effects: bronchitis, infection vulnerability, and potential cancer risk. Non-combustion methods (vaporization, edibles) could mitigate these risks.
What This Study Doesn't Tell Us
Brief review format limits depth. Does not systematically weigh conflicting evidence (some large studies found no cancer link). Cannot fully separate cannabis effects from tobacco effects. Does not address dose-response relationships or the effects of vaporization versus smoking.
Questions This Raises
- ?Do the respiratory risks of cannabis smoking outweigh the medical benefits for patients who could use non-combustion alternatives?
- ?Would long-term prospective studies of cannabis-only smokers clarify the cancer risk?
- ?How do modern high-potency products affect respiratory risk?
Trust & Context
- Key Stat:
- Cannabis smoke causes bronchitis symptoms, immune suppression, and potential but inconclusive lung cancer risk.
- Evidence Grade:
- Moderate evidence from a narrative review synthesizing immunohistopathological and epidemiological data, though the review is brief and does not systematically assess evidence quality.
- Study Age:
- Published in 2016. Respiratory effects of cannabis continue to be studied as use patterns and product types evolve.
- Original Title:
- Damaging Effects of Cannabis Use on the Lungs.
- Published In:
- Advances in experimental medicine and biology, 952, 31-34 (2016)
- Authors:
- Yayan, Josef, Rasche, Kurt
- Database ID:
- RTHC-01310
Evidence Hierarchy
Summarizes existing research on a topic.
What do these levels mean? →Frequently Asked Questions
Does smoking cannabis damage your lungs?
Yes. This review found cannabis smoke causes bronchitis symptoms, can weaken lung immunity leading to pneumonia, and may cause airway obstruction with heavy long-term use. The cancer risk is possible but not proven conclusively.
Is cannabis smoke as harmful as tobacco smoke?
Cannabis smoke produces many of the same harmful effects on the lungs (bronchitis, cough, sputum). However, some large studies have not found the same degree of lung function decline as with tobacco. The cancer risk from cannabis is still debated, while tobacco's cancer risk is firmly established.
Read More on RethinkTHC
- cannabis-cardiovascular-heart-risk-stroke
- cannabis-heart-cardiovascular-risk
- coughing-up-stuff-after-quitting-weed
- lung-recovery-after-quitting-smoking-weed
- lung-recovery-quitting-weed
- quitting-weed-female-hormones
- quitting-weed-weight-gain-loss-diet-appetite
- sex-after-quitting-weed
- weed-DUI-driving-impaired-cannabis-laws
- weed-acne-skin
- weed-fertility-sperm
- weed-gut-digestion-problems
- weed-heart-health
- weed-testosterone-levels
- how-to-tell-if-weed-is-moldy
Cite This Study
https://rethinkthc.com/research/RTHC-01310APA
Yayan, Josef; Rasche, Kurt. (2016). Damaging Effects of Cannabis Use on the Lungs.. Advances in experimental medicine and biology, 952, 31-34.
MLA
Yayan, Josef, et al. "Damaging Effects of Cannabis Use on the Lungs.." Advances in experimental medicine and biology, 2016.
RethinkTHC
RethinkTHC Research Database. "Damaging Effects of Cannabis Use on the Lungs." RTHC-01310. Retrieved from https://rethinkthc.com/research/yayan-2016-damaging-effects-of-cannabis
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.