50% of patients with uncontrolled asthma smoke cannabis, shows new survey

Reviewed by Emily Henderson, B.Sc.Feb 2 2021

As the number of states increases where medical and recreational cannabis use is legal, so does the importance that physicians discuss with patients the effects of cannabis on those with asthma.

A new survey in Annals of Allergy, Asthma and Immunology, the scientific journal of the American College of Allergy, Asthma, and Immunology, shows that of those who used cannabis, about half smoked it while a third vaped - both "inhalation routes" likely to affect one's lungs.

"It surprised me that over half of the cannabis users in this study who have asthma were smoking it," said Joanna Zeiger, Ph.D., principal investigator for the study. "And further, of those with uncontrolled asthma, half reported smoking cannabis. We also found that people with asthma are not routinely being asked or advised by their physician about cannabis and how they are consuming it."

Eighty-eight (18%) of the 489 adults with allergy/asthma who completed the survey reported current cannabis use. The majority of those responding were younger than 50 years, female, and White. Among non-cannabis users, 2.5% reported an allergy to cannabis.

Two-thirds of current cannabis users did so for medical or medical/recreational purposes. The anonymous survey, conducted in collaboration with Allergy & Asthma Network, was of those 18 years and older and looked at cannabis knowledge, attitudes, and patterns of use.

"Strikingly, among current cannabis users, only about 40% report having their physicians inquire about cannabis use, and about the same number of patients want to discuss cannabis with their physicians," says allergist William Silvers, MD, study co-author, ACAAI member, and expert on cannabis allergy.

"In order to more completely manage their allergy/asthma patients, allergists should increase their knowledge about cannabis and inquire about cannabis use including types of cannabinoid, route of use, reasons for use, and adverse effects," says Dr. Silvers. "As with cigarette smoking, efforts should be made to reduce smoking of cannabis, and recommend other potentially safer routes such as edibles and sublingual tinctures."

Positive effects of cannabis use (e.g., reduced pain, calm, improved sleep) were reported significantly more frequently than adverse effects (e.g., cough, increased appetite, anxiety). Of concern, about 20% of survey respondents reported coughing from cannabis, which was significantly related to smoking cannabis.

Almost 60% of the cannabis users in the survey reported current asthma, of whom 40% were uncontrolled by the Asthma Control Test.

We look forward to future studies of larger, more diverse cohorts to better explore more deeply the effect of cannabis use on asthma and other allergic disorders."

Joanna Zeiger, PhD, Study Principal Investigator,

Allergists are specially trained to diagnose and treat asthma. To find an allergist near you who can help create a personal plan to deal with your asthma and help you live your best life, use the ACAAI allergist locator.