Cannabis and Lung Health

Weed, pot, marijuana. Whatever you call it, cannabis is a legal substance with many potential therapeutic uses – but also many potential lung health risks. It is most commonly smoked or vaped, but other non-inhaled methods exist, too.

Read on to better understand the risks of smoking cannabis – and get practical advice to become a hero to your lungs.

Cannabis and Lung Health

Weed, pot, marijuana. Whatever you call it, cannabis is a legal substance with many potential therapeutic uses – but also many potential lung health risks. It is most commonly smoked or vaped, but other non-inhaled methods exist, too.

Read on to better understand the risks of smoking cannabis – and get practical advice to become a hero to your lungs.

Follow the (mis)Adventures of the toker

Showdown!

Tobacco vs Cannabis

Myth

Cannabis smoke is riskless, especially when compared to known respiratory scourges like cigarette smoke.

Fact

Smoking cannabis has two things 6 going against it.

1. People tend to inhale deeply and for longer periods when using cannabis (vs. when smoking cigarettes)

2. Cannabis is smoked at higher temperatures, without filters, and to a shorter butt length when in joint form.

This means that the harmful substances lurking in cannabis smoke have more time and opportunity to wreak havoc on your lungs.

Cannabis smoke also shares more than a few common toxic ingredients with tobacco smoke7 – and some in even greater quantity!

30% more TAR than a typical cigarette
500% more HYDROGEN CYANIDE than a typical cigarette
1900% more AMMONIA than a typical cigarette

Unmasking the Risks

Smoking is the most harmful method of consuming cannabis, with both short-term and long-term effects on your lung health. Know the risks of using cannabis before it slows you down:

Airways and Injuries

Physical changes to the lungs are the arch nemesis of healthy breathing, meaning you may eventually be battling coughing, wheezing, shortness of breath and worsening asthma symptoms. You could even develop symptoms of chronic bronchitis.1

Excess Sputum

Sputum (alias: phlegm) is the sidekick you never asked for. It’s a mixture of saliva and thick mucus coughed up from the lower respiratory tract.2

Bronchospasms

Good lungs may find themselves squaring off against bronchospasms – a sudden tightening of the muscles in the walls of your airways – leaving you fighting for air.3

Infections

Changes to your lungs’ immune cells up your risk of facing off against infectious foes like pneumonia, or even fungal or bacterial pathogens (5) from the cannabis plants. Sharing pipes or bongs increases your risk of tuberculosis, too.4

CAN CANNABIS CAUSE

LUNG CANCER?

We don’t know – yet.

According to the Centre for Medicinal Cannabis Research at McMaster University,
there have been around 12 studies that investigated the link between cannabis and lung cancer.

To be continued…

Eight studies

noted an increase in lung cancer risk from cannabis.*

Four Studies

found either no significant association or a lower risk for lung cancer.

Bottom line

Cannabis use may increase your lung cancer risk, but so far, the evidence is inconsistent. More research is needed.

*  In those studies that noted an increased risk, these ranged from 2 to 4-fold increased risk of lung cancer in cannabis smokers, but were not methodologically as strong as those studies finding no increases in cancer risk.
Lungs

Eight studies

noted an increase in lung cancer risk from cannabis.*

Four Studies

found either no significant association or a lower risk for lung cancer.

Bottom line

Cannabis use may increase your lung cancer risk, but so far, the evidence is inconsistent. More research is needed.

*  In those studies that noted an increased risk, these ranged from 2 to 4-fold increased risk of lung cancer in cannabis smokers, but were not methodologically as strong as those studies finding no increases in cancer risk.
Lungs

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The Ontario Lung Association

The Ontario Lung Association is a not-for-profit organization dedicated to helping all Ontarians breathe. We achieve this by promoting healthy breathing, supporting those living with lung disease and finding future solutions. All of this is done with the goal of delivering a future of better breathing for all.

Our Sidekicks

British Columbia Lung Association – Manitoba Lung Association – Lung Association of Saskatchewan

The Toker was made possible through a financial contribution from Health Canada.

The views expressed herein do not necessarily represent the views of Health Canada.

The Science

The Ontario Lung Association would like to thank all researchers who are working tirelessly to investigate the lung health effects of cannabis. They are proof that not all heroes wear capes.

1 Tashkin Donald P. Effects of marijuana smoking on the lung. Annals of the American Thoracic Society. 2013 Jun;10(3):239-47. doi: 10.1513/AnnalsATS.201212-127FR
2 Hancox RJ, Shin HH, Gray AR, Poulton R, Sears MR. Effects of quitting cannabis on respiratory symptoms. European Respirology Journal. 2015;46(1):80-87. doi:10.1183/09031936.00228914.
3 Gates P, Jaffe A, Copeland J. Cannabis smoking and respiratory health: Consideration of the literature. Respirology. 2014;19(5):655-662. doi:10.1111/resp.12298.
4 Ibid.


5 Ibid.