Cannabusters myth #11: Smoking cannabis causes more lung damage than tobacco

Oct 3 2018, 8:00 pm

Every day, in every way, cannabis legalization in Canada is getting closer. But despite all the hype, noise, and publicity, there seem to be recurring cannabis myths flying around that just won’t quit.

With 10 days to go until federal legalization, Grow’s daily Cannabusters series tackles common myths by cutting through the stigma and sensationalism to bring you the facts about cannabis.

Myth: Smoking cannabis causes more lung damage than smoking tobacco

Fact: It’s the opposite, although neither is ideal from a respiratory-health perspective.

Regardless of what you’re rolling up, smoking things isn’t good for you – period.

But does smoking cannabis cause as much (or more) damage than smoking tobacco?


There are multiple studies that have shown the opposite to be true.

A 2012 UCSF study, for example, measured the air flow rate and lung volume in tobacco and cannabis smokers over a 20-year period and compared results.

Tobacco smokers showed a decrease in both indicators, with heavier smokers showing more significant decreases. Cannabis smokers, however, actually saw an increase in air flow rate with increased exposure to the drug. The researchers were unable to explain this, although they cited the discrepancy between quantities of tobacco or cannabis smoked by both groups as a possible contributing element.

Another 2012 study by the US government found that smoking cannabis regularly does “not impair lung function,” and that cannabis smokers had marginally superior results in a lung function test than their non-smoking contemporaries.

It’s well-established that smoking tobacco can cause respiratory cancers, and tobacco smoke is full of carcinogens. Strangely – despite cannabis smoke containing considerably more carcinogens than tobacco smoke – there is no credible evidence that smoking cannabis causes cancer. While scientists are unsure of exactly why that is, it’s hypothesized that cannabinoid THC may possess some kind of protective quality – in addition to its acute bronchiodilator effect, anti-inflammatory, and analgesic properties.

That said, inhaling combustible matter is bad for your respiratory system.

Chronic, heavy cannabis use can result in respiratory irritation, chronic bronchitis, or even – if the individual is immunocompromised – increase the chance of a respiratory infection.

A 2016 National Health Institute study found that despite the fact that it causes less damage than tobacco, researchers were reviewing “evidence that chronic cannabis users have an increased incidence of respiratory symptoms such as chronic cough, sputum production, dyspnoea, hoarse voice and chest tightness.”


They also found that “it was observed that cannabis smoke produces large airway epithelial damage, edema, erythema and increased secretions with goblet cell hyperplasia, loss of ciliated epithelium and squamous metaplasia on biopsy.”

So how can one avoid or diminish the possibility of increased secretions and a voice like Marge Simpson? Cannabis users can do some damage control by keeping tobacco out of joints, vaping instead of smoking, or experimenting with edibles and oils – at least some of the time.

Do it for your sputum production.

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Emma SpearsEmma Spears

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