Regularly inhaling cannabis increases risk of asthma, according to largest study of its kind – CTV
September 22, 2025
New research suggests smoking or vaping cannabis products regularly may put users at a greater risk of developing asthma.
The study by University of California, San Francisco connected the inhalation of cannabis on a daily basis with a 44 per cent increase in the chance of developing asthma.
Researchers said in a news release Friday that inhaling marijuana every day also amplified the risk of developing obstructive pulmonary disease (COPD) by 27 per cent. In fact, that risk may be understated, they said, since it takes the condition decades to develop and researchers didn’t have detailed information around how long study participants had been using the drug.
For the purposes of this research, “inhaling” covered various methods of cannabis use, including smoking, vaping and dabbing, which involves breathing in vapours from a concentrated form of cannabis.
The study, published in the Journal of General Internal Medicine, also found a link between higher risks to a person’s lungs and inhaling cannabis, even for those who had never smoked cigarettes, researchers said. It is the largest study of its kind, involving 380,000 American adults, nearly 222,000 of whom had never smoked tobacco.
