The study, published this week in the Journal of General Internal Medicine, found that daily cannabis inhalation was linked to a 44 percent higher likelihood of developing asthma and a 27 percent increased chance of chronic obstructive pulmonary disease (COPD). COPD is a group of conditions—including emphysema and chronic bronchitis—that can take decades to develop, meaning the true risk could be even greater than reported.
Researchers defined cannabis inhalation as smoking, vaping or “dabbing,” a method of inhaling concentrated marijuana vapor. The findings held true even among people who had never smoked tobacco, a group often overlooked in studies of respiratory health.
Among non-smokers, the risks were even more striking. Daily cannabis use was associated with a 51 percent higher chance of developing asthma. While COPD rates were also elevated, the increase did not reach statistical significance in that subgroup.
The research drew on data from more than 380,000 U.S. adults who participated in the Behavioral Risk Factor Surveillance System, a national survey conducted by the Centers for Disease Control and Prevention. Nearly 222,000 of those surveyed had never smoked cigarettes, making the analysis the largest of its kind to explore cannabis-related lung risks independent of tobacco.
Experts say the findings underscore a growing public health concern. With marijuana now legal for recreational use in most states and widely perceived as safer than tobacco, many users may not realize the potential harms of inhalation.
“The message about smoking tobacco being bad for you has gotten out there, but for cannabis, it’s much less clear,” said Dr. Alison Rustagi, lead author and assistant professor at UCSF.
Rustagi urged caution for current and prospective cannabis users. “If people are looking to reduce their likelihood of developing a chronic lung disease, they should not start using cannabis,” she said. “And if they already smoke cannabis, they should do it less often.”
Read the whole study from UCSF here.
