According to a new study published in the journal Respiratory Medicine the long-term inhalation of marijuana smoke does not impact lung function.
For the study Australian researchers examined “whether cigarette smoking or cannabis use and co-use are each associated with lung function in a population sample of young adults.”
The data used by researchers is from a prospective cohort study of cigarette smoking, cannabis use and co-use at 21 and 30 years of age and lung function measured at 30 years.
Researchers found that cigarette-only smokers “already showed evidence of impaired lung function” at age 30. By contrast, “those who have [only] used cannabis ever since the adolescent period do not appear to have evidence of impairment of lung function.” Researchers identified airflow obstructions in the lungs of cigarette-only smokers but found no such obstructions in cannabis-only subjects.
“Co-use of tobacco and cannabis does not appear to predict lung function beyond the effects of tobacco use alone”, states the study.
“Cigarette smoking (with or without cannabis use) is associated with reduced airflow”, notes researchers. “There is no consistent association between cannabis use and measures of lung function. The co-use of tobacco and cannabis appears to entail no additional risk to lung function beyond the risks associated with tobacco use alone.”
Researchers conclude by stating: “Persistent cigarette smoking is associated with reduced airflow even in young adults. Cannabis use does not appear to be related to lung function even after years of use.”
The study’s full abstract can be found below.
Abstract
Background: Use of tobacco and cannabis is common and has been reported to predict lung function. Less is known about co-use of tobacco and cannabis and their impact on changes in lung function to early adulthood.
Research question: The study examines whether cigarette smoking or cannabis use and co-use are each associated with lung function in a population sample of young adults.
Study design and methods: Data are from a prospective cohort study of cigarette smoking, cannabis use and co-use at 21 and 30 years of age and lung function (FVC, FEV1, FEV1/FVC) measured at 30 years. Lung function results are transformed using Global Lung Function Formulae. Subjects are the children of pregnant women who were recruited into the cohort study over the period 1981-3. Respondents were administered a spirometry assessment at 21 and 30 years of age. These respondents completed a smoking and cannabis use questionnaire at 21- and 30-year follow-ups.
Results: Cigarette smoking (with or without cannabis use) is associated with reduced airflow. There is no consistent association between cannabis use and measures of lung function. The co-use of tobacco and cannabis appears to entail no additional risk to lung function beyond the risks associated with tobacco use alone.
Interpretation: Persistent cigarette smoking is associated with reduced airflow even in young adults. Cannabis use does not appear to be related to lung function even after years of use.
