Regular cannabis use linked to asthma, COPD, and pneumonia even without tobacco

Regular cannabis use was significantly associated with higher risk of asthma, COPD, and pneumonia regardless of whether the person also used tobacco, based on electronic health records of nearly 9,000 cannabis users.

Winhusen, Theresa et al.·Drug and alcohol dependence·2019·Moderate EvidenceRetrospective Cohort
RTHC-02350Retrospective CohortModerate Evidence2019RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Retrospective Cohort
Evidence
Moderate Evidence
Sample
Not reported

What This Study Found

Regular cannabis use was associated with increased risk of asthma (OR 1.32-1.50), COPD (OR 1.44-2.17), and pneumonia (OR 1.80-2.13) across all groups. Importantly, cannabis users without tobacco use disorder still showed elevated respiratory disease risk: asthma OR 1.32, COPD OR 2.17, pneumonia OR 2.13. Tobacco users had the highest overall prevalence regardless of cannabis status.

Key Numbers

8,932 cannabis users total. 4,678 with tobacco use disorder. 4,254 without tobacco use disorder. Non-tobacco cannabis users: asthma OR 1.32, COPD OR 2.17, pneumonia OR 2.13.

How They Did This

Retrospective analysis using IBM Watson Health Explorys electronic health records. 8,932 cannabis-using patients matched to controls using propensity score methods, controlling for demographics, zip code income, BMI, and tobacco status.

Why This Research Matters

Most studies of cannabis and respiratory disease are confounded by concurrent tobacco use. This study specifically examined cannabis users without tobacco use disorder and still found elevated respiratory risk.

The Bigger Picture

The finding that cannabis alone (without tobacco) is associated with respiratory disease challenges the common belief that cannabis smoking is less harmful to the lungs than tobacco.

What This Study Doesn't Tell Us

Retrospective EHR data. Cannabis use identified by diagnosis codes and urine screens, which may miss occasional users or include former users. Cannot determine method of cannabis consumption. Residual confounding possible.

Questions This Raises

  • ?Would non-smoked cannabis (edibles, tinctures) show the same respiratory associations?
  • ?Is there a dose-response relationship?

Trust & Context

Key Stat:
COPD risk doubled for cannabis users without tobacco
Evidence Grade:
Large matched cohort from electronic health records with propensity score methods, though subject to EHR data limitations.
Study Age:
2019 study.
Original Title:
Regular cannabis use, with and without tobacco co-use, is associated with respiratory disease.
Published In:
Drug and alcohol dependence, 204, 107557 (2019)
Database ID:
RTHC-02350

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-ControlFollows or compares groups over time
This study
Cross-Sectional / Observational
Case Report / Animal Study

Looks back at existing records to find patterns.

What do these levels mean? →

Frequently Asked Questions

Does cannabis cause lung disease without tobacco?

This study found cannabis users without tobacco use disorder had significantly higher rates of asthma (OR 1.32), COPD (OR 2.17), and pneumonia (OR 2.13) compared to matched controls.

How does cannabis compare to tobacco for lung risk?

Tobacco users had the highest overall respiratory disease rates, but cannabis users without tobacco still showed elevated risk, suggesting cannabis has independent respiratory effects.

Read More on RethinkTHC

Cite This Study

RTHC-02350·https://rethinkthc.com/research/RTHC-02350

APA

Winhusen, Theresa; Theobald, Jeff; Kaelber, David C; Lewis, Daniel. (2019). Regular cannabis use, with and without tobacco co-use, is associated with respiratory disease.. Drug and alcohol dependence, 204, 107557. https://doi.org/10.1016/j.drugalcdep.2019.107557

MLA

Winhusen, Theresa, et al. "Regular cannabis use, with and without tobacco co-use, is associated with respiratory disease.." Drug and alcohol dependence, 2019. https://doi.org/10.1016/j.drugalcdep.2019.107557

RethinkTHC

RethinkTHC Research Database. "Regular cannabis use, with and without tobacco co-use, is as..." RTHC-02350. Retrieved from https://rethinkthc.com/research/winhusen-2019-regular-cannabis-use-with

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.