Does smoking weed benefit the respiratory system, including the lungs? No, that's not true: While researchers believe that more research is needed to determine both the health benefits and adverse effects of cannabis smoke inhalation, there is no evidence to suggest that smoke inhalation leads to better health.
The claim appeared in a Facebook post (archived here) published on January 10, 2022. The post has a photo of a woman appearing to exhale smoke with text that reads:
Smoking weed has been shown to benefit the respiratory system including the lungs
This is what the post looked like on Facebook on January 12, 2022:
(Source: Facebook screenshot taken on Wed Jan 12 17:50:48 2022 UTC)
The post offers no information or evidence to substantiate or explain its "has been shown ..." claim.
The American Lung Association said such inhalation "clearly damages the human lung" in a statement titled "Marijuana and Lung Health" that was last updated on December 17, 2020. The organization cited a few of the available studies about cannabis smoke inhalation and encouraged the public not to smoke marijuana.
In a similar statement that was last updated on January 8, 2021, the Canadian Lung Association cautions the public against smoking cannabis because of its potential risks to lung health.
Both statements said that in general, the combustion of materials leads to the release of carcinogens and toxins. They also mentioned that some early studies have linked cannabis smoking to chronic bronchitis. However, both organizations called for more research that explores the effects of cannabis.
In an email to Lead Stories on January 12, 2022, Donald Tashkin, a pulmonologist and distinguished emeritus professor of medicine at UCLA whose study "Effects of Marijuana Smoking on the Lung" is cited in statements by both lung associations, said there is a "general consensus that marijuana increases the risk of chronic bronchitis, a finding that is supported by visual and microscopic evidence of injury to the large airways." Data about marijuana's relationship to chronic obstructive pulmonary disease and lung cancer and data on marijuana's immunosuppressive properties are less clear, he said.
Lead Stories also contacted Oyedeji Ayonrinde, an associate professor in the Department of Psychiatry at Queen's University who specializes in cannabis education. In an email on January 12, 2022, he said:
Generally speaking. Smoking in any form does not benefit the lungs.
I find the claim inaccurate, misleading if not potentially dangerous to people who may have respiratory disease or compromised breathing.
I agree with the statement by the Canadian Lung Association.
Ayonrinde mentioned that because cannabis smoking is "not a single method, single product process," several factors can contribute to how cannabis smoke inhalation affects an individual's respiratory health. Such considerations include the method used to smoke and the coughing associated with smoke inhalation.
Lead Stories reached out to the American Lung Association and the Canadian Lung Association to determine whether the organizations have any updated information on cannabis smoke inhalation and its effects on the respiratory system. We will add to this story if they respond.