Study: Cannabis smoking doesn't increase chances of getting COPD in tobacco smokers

Chronic Obstructive Pulmonary Disease (COPD) has been linked to tobacco smoking, yet data on cannabis smoking is not prevalent. This longitudinal study's intent was to help collect new data in this area.  It was published online ahead of print in the journal Chronic Obstructive Pulmonary Diseases in May 2023.

The study divided 1863 long-term tobacco smokers into 3 groups based on self-reported cannabis use:

  • CURRENT marijuana smokers (CMS)
  • FORMER marijuana smokers (FMS)
  • NEVER marijuana smokers (NMS)


Participants were followed for at least one year, although most were followed for over 4 years. The average follow-up time was 4.2 years.

The metrics they used were based on tests and practitioner observations for the following:

  • changes in spirometry (type of breathing test)
  • symptoms
  • health status
  • radiographic (type of X-ray) metrics


In the authors' words:

neither former nor current marijuana smoking of any lifetime amount was associated with evidence of COPD progression or its development.


The full text pdf paper is here at