From symptoms to mechanisms: multidimensional insights into cannabis smoke

Extract Cannabis is now the most widely used psychoactive substance globally, with an estimated 228 million users and increasing prevalence following legalisation across several nations [1]. In Canada, where recreational cannabis was legalised in 2018, more than one-third of young adults report annual use, with smoking remaining the most common route of consumption [2]. Despite this widespread uptake, public perceptions of cannabis as a “safer” alternative to tobacco persist, even though combustion releases many of the same toxicants found in cigarette smoke [3]. Epidemiological studies have linked smoking (e.g. cannabis, tobacco) to increased respiratory symptoms, but evidence regarding lung function impairment and chronic respiratory disease (e.g. COPD) risk has been inconsistent [4–7]. Most prior work relied primarily on spirometry, which may fail to capture small airway disease, a key site of early pathology in obstructive lung disease [4, 8]. Additionally, concurrent tobacco and vaping exposures complicate attribution of cannabis-specific effects [9]. Against this backdrop, the Canadian Users of Cannabis Smoke (CANUCK) study provides a timely and multidimensional assessment of the respiratory impact of cannabis smoking, using advanced imaging and molecular profiling to complement clinical characterisation.