A Growing Habit
On October 17, 2018, Canada became the second nation in the world to legalize recreational cannabis. Only half a year after legalization, 18% or 5.3 million Canadians already reported using cannabis, primarily through smoking.
Given that 4.9 million Canadians smoke cigarettes, these statistics indicate that cannabis smoking has already surpassed cigarette smoking. Yet while the popularity of tobacco smoking has steadily fallen over the years, the number of people smoking cannabis is only expected to increase.
Too Many Unknowns
Despite the legalization of recreational cannabis and its increasing popularity, there is little to no information about the impact of cannabis smoking on lung health. Public perception of cannabis smoking has become more and more favourable over time, with the proportion of subjects perceiving its associated risks declining – only 40% of regular cannabis smokers believe that it causes considerable harm to their lungs. Given the well-documented health effects of smoking and tobacco use (including cancer, heart disease and lung disease, among others), this is a cause for major concern.
Need for New Evidence
In response to this lack of concrete evidence on health and safety effects of cannabis, the Canadian Institutes for Health Research (CIHR) committed $19.5 million to support 13 studies focusing on understanding the health, safety, as well as behavioural, social, cultural, ethical and economic impacts of cannabis legalization. Centre for Heart Lung Innovation researcher Dr. Janice Leung and co-applicants Drs. Don Sin, Wan Tan, Jonathon Leipsic, Andrea Gershon, Miranda Kirby, Grace Parraga, and Mohsen Sadatsafavi, were ranked the top application out of 52 proposals.
Canadian Users of Cannabis Smoke (CANUCK) Study
Dr. Leung’s study, entitled Canadian Users of Cannabis Smoke (CANUCK): Impact on Lung Health via Clinical, Imaging, and Biologic Measures, will study the effects of cannabis smoking on lung health. The CANUCK study will use a combination of clinical measures, state-of-the-art imaging systems, and molecular profiling to measure the health outcomes and extent of structural and cellular damage to the lungs of cannabis smokers.
“Our goal is to figure out whether cannabis smoking has a detrimental impact on lung function and respiratory health in a way that might be similar to tobacco smoking.”
“This new funding will allow us to gain a really complete understanding of cannabis smoking, from how much it costs our health care system all the way down to how it might change the cells in your lung. This information will help to better inform Canadians about the consequences of cannabis smoking.”Dr. Janice Leung, lead investigator of the CANUCK study.