New research shows tobacco poses more risk to lungs than a joint

Cannabis over tobacco: photo of farmer handing a joint through cannabis plants

The potential harms of smoking tobacco are highly studied and recorded, but the same isn’t true of smoking cannabis. Despite the differences between smoking commercial tobacco and lighting a joint of regulated cannabis flower, people lump all smokers together. However, without extensive research on the pulmonary impact of cannabis combustion, most consumers err on the side of caution.

However, recent pre-proof research from the COPD Foundation suggests that smoking cannabis may not pose the same risk to lung health that smoking tobacco does.

This study aimed to monitor how cannabis consumption impacts the development of chronic obstructive pulmonary disease (COPD). To do this, researchers sought out patients diagnosed with or at high risk for COPD, excluding patients with asthma. Participants fell into three categories: those who used to smoke cannabis, those who still do, and patients who had never consumed.

Then the team split the cohort to reflect lifetime cannabis history, or “joint-years,” to mark lifetime experience with the plant. The study calculated the number of joints smoked per day by the years of regular cannabis use and dubbed the resulting number as joint-years.

A bowl of cannabis packed in a bong or pipe was considered one joint for the equation. After calculating their age in joints, the study divided participants into four sets of joint-years ranging from zero to 20+.

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Researchers collected a variety of data to ascertain how cannabis smoking impacted pulmonary health, including St. George’s Respiratory Questionnaire (SGRQ), the modified Medical Research Council (mMRC) scale, COPD Assessment Test (CAT), and inflamed COPD symptoms.

In addition, doctors measure the forced expiratory volume (FEV), or how much air someone can exhale at once. Data from quarterly follow-up visits over four or more years were then collected and analyzed.

To understand whether cannabis use would impact the development of COPD in tobacco-smoking participants, researchers measured the time to develop airflow obstruction using FEV percentages.

The study revealed that cannabis consumption had no statistically relevant effect on the development of COPD in tobacco smokers. Current cannabis smokers did show a higher propensity to develop a cough compared to former consumers and those who abstain altogether.

This study shows no correlation to the exacerbation of COPD in at-risk or diagnosed patients who smoke tobacco. This pre-proof study adds to past research covering the pulmonary impact of cannabis smoking among patients that did not smoke tobacco.

Though results are promising, there were study limitations worth recognizing. First, the sample size was “relatively small” with a short follow-up duration. As such, investigators consider the findings exploratory, hoping they will inspire more research.

Additionally, marijuana use is highly subjective. The amount of smoke delivered by the numerous methods of cannabis consumption varies widely. Consumption was also self-reported, which leaves room for error.

While all smoking carries pulmonary health risks, these findings show that cannabis has a less damaging effect on the lungs than tobacco smoke. With a lack of research on the topic, this study is welcome, but try not to pass the joint to granny on the oxygen tank. Vaporizers and edibles remain the ideal option for people with compromised lungs.

Cara Wietstock is Senior Content Producer of and has been working in the cannabis space since 2011. She has covered the cannabis business beat for Ganjapreneur and The Spokesman Review. You can find her living in Bellingham, Washington with her husband, son, and a small zoo of pets.