The long-term use of marijuana isn’t associated with a decrease in lung function, and may reduce the risk of emphysema, according to a new study[1] published by the journal Chronic Obstructive Pulmonary Diseases.

Study: Long-Term Marijuana Use Doesn’t Increase Risk for Adverse Lung Function, May Reduce Emphysema Risk For the study, researchers examined the relationship between the long-term use of marijuana and lung health in 2,300 patients ages 40 to 80.

“This cross-sectional analysis of participants enrolled into the SPIROMICs cohort was performed to investigate the relationships between marijuana use and pulmonary function and symptoms”, states the study, which notes that “Those enrolled were carefully screened and recruited based on tobacco use history and spirometric function”.

According to researchers; “Neither current nor former marijuana use was associated with increased risk of cough, wheeze, or chronic bronchitis when compared to never marijuana users after adjusting for covariates”. Both current and former marijuana use “was associated with significantly less quantitative emphysema”. In agreement with other published studies, researchers “also did not find that marijuana use was associated with more obstructive lung disease.”

The full text of the study can be found by clicking here[2]. It was conducted by researchers from the following institutions:


  1. National Jewish Health, Denver, Colorado
  2. Department of Epidemiology, Colorado School of Public Health, University of Colorado Anschutz Medical Campus, Aurora
  3. Division of Pulmonary and Critical Care Medicine, David Geffen School of Medicine, University of California at Los Angeles
  4. Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine and Cardiovascular Research Institute, University of California San Francisco, School of Medicine, San Francisco
  5. Departments of Radiology, Medicine and Biomedical Engineering, University of Iowa, Iowa City
  6. University of Utah Health Sciences Center, Salt Lake City
  7. Department of Biostatics and Informatics, Colorado School of Public Health, University of Colorado Anschutz Medical Campus, Aurora
  8. Division of Pulmonary Diseases and Critical Care Medicine, University of North Carolina at Chapel Hill
  9. Columbia University, Division of General Medicine, New York, New York
  10. University Michigan Health System, Ann Arbor
  11. Johns Hopkins University, Baltimore, Maryland


  1. ^ new study (
  2. ^ clicking here (
  3. ^ Anthony Martinelli (

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