Marijuana can be more harmful to smokers’ lungs and airways than tobacco, according to a small Canadian study published Tuesday.
Researchers from the University of Ottawa and the Ottawa Hospital looked at chest X-rays of 56 smokers, 57 non-smokers and 33 smokers between 2005 and 2020.
They found higher rates of airway inflammation and emphysema – a chronic lung disease – among regular smokers compared to smokers and non-smokers.
“Marijuana smoking is increasing and there is a public perception that marijuana is safe, or that it is safer than cigarettes,” Giselle Revah, a radiologist at the Ottawa hospital, where the study was conducted, told AFP.
“But this study raises concerns that this may not be true.”
He said the higher levels of inflammation and disease among marijuana smokers versus tobacco may be related to differences in how the drug is used.
“Cannabis is released without filtering, as opposed to tobacco which is usually filtered,” he said. “When you smoke unfiltered marijuana, a lot of particulate matter gets in your way, gets deposited there and irritates your airways.”
Also, he added, “people often take a deep breath and hold the smoke in their lungs for a long time because of marijuana, which can cause severe respiratory distress.”
Although possible explanations, the authors of the study, which were published in the magazine Radiologythey also noted that some of the marijuana smokers also smoked cigarettes, and that some lung machines produced ambiguous results, suggesting that more study is needed.
As Revah pointed out, there is very little research on the health benefits of cannabis, as it is illegal in many countries.
Canada, where the researchers are from, legalized the use of cannabis in 2018.
It is also legal for recreational use in Uruguay and Mexico, among other countries, and in many US states, while several other states and territories have recently banned possession of the drug or allowed it to be used medicinally.
© Agence France-Presse
