A major new systematic review and meta-analysis, recently published in the prestigious peer-reviewed journal Heart, has synthesized data from 24 high-quality observational studies involving a combined total of approximately 200 million individuals. The vast majority of participants were adults aged between 19 and 59 years, drawn from diverse populations across multiple countries, including the United States, Canada, France, and several others.
This large-scale pooled analysis specifically investigated whether cannabis use is associated with an elevated risk of serious and potentially life-threatening cardiovascular outcomes. The primary endpoints examined included cardiovascular disease mortality (death caused by heart disease or related conditions), acute coronary syndrome (which encompasses heart attacks and other sudden coronary events), and stroke (both ischemic and hemorrhagic).
The results were striking and concerning: compared with people who do not use cannabis, those who reported any level of cannabis consumption exhibited substantially higher risks across all the major cardiovascular endpoints studied. Most alarmingly, the odds of dying from cardiovascular disease were roughly doubled among cannabis users, with a pooled risk ratio of approximately 2.10. In addition, cannabis use was linked to a 29% increased risk of experiencing acute coronary events (such as myocardial infarction) and a 20% higher risk of suffering a stroke.
Importantly, these associations persisted even when the researchers restricted their analyses to prospective cohort studies (which follow participants over time and are generally considered more reliable for establishing temporal relationships than cross-sectional data). This consistency across different study designs and large real-world populations strengthens confidence in the overall pattern of findings.The authors emphasize that these elevated risks were observed regardless of the method of cannabis consumption—whether smoked, vaped, or ingested in edible form. This suggests that the cardiovascular effects are not solely attributable to the combustion byproducts of smoking (as seen with tobacco), but are likely driven, at least in part, by the pharmacological actions of cannabis compounds themselves, particularly delta-9-tetrahydrocannabinol (THC) and possibly other cannabinoids.Biological mechanisms that could explain these associations include several well-documented physiological effects of cannabis on the cardiovascular system. Acute use can cause significant increases in heart rate (tachycardia) and changes in blood pressure (both elevations and, in some cases, orthostatic drops), as well as alterations in vascular tone and endothelial function. THC and related compounds may also promote systemic inflammation, increase platelet activation and pro-thrombotic tendencies, induce oxidative stress, and trigger acute hemodynamic instability—all of which could precipitate plaque rupture, thrombosis, or ischemic events in susceptible individuals.
A particularly noteworthy aspect of the findings is that these risk elevations were apparent even among relatively younger adults and in people without established prior heart disease or heavy concurrent tobacco smoking. While many of the included studies adjusted for a range of potential confounding factors (such as age, sex, body mass index, physical activity, alcohol use, and tobacco exposure), the observational nature of the data means that residual confounding from unmeasured lifestyle variables, socioeconomic factors, or other behaviors cannot be entirely ruled out.Nevertheless, the sheer scale of the pooled dataset, the geographic and demographic diversity of the populations studied, and the consistency of the results across different analytic approaches all point toward a meaningful association between cannabis use and adverse cardiovascular outcomes. While observational studies can demonstrate correlation but cannot definitively prove causation, the strength, dose-response patterns in some studies, biological plausibility, and reproducibility of the findings collectively raise serious concerns about potential harm.In light of rapidly increasing cannabis legalization, normalization, and use worldwide—particularly among younger adults—the authors and other cardiovascular health experts are calling for greater public awareness and clinical vigilance. Individuals with existing cardiovascular risk factors (such as hypertension, diabetes, high cholesterol, family history of early heart disease, or prior cardiac events) are especially encouraged to exercise caution. The growing body of evidence suggests that regular or heavy cannabis consumption may contribute to poorer heart health outcomes over time.Health professionals are increasingly recommending that patients openly discuss their cannabis use (including frequency, method, and potency) with their doctors so that risks can be properly assessed and individualized advice provided. As more high-quality research emerges—including prospective studies with better control of confounders and mechanistic investigations—the relationship between cannabis and cardiovascular health is likely to become even clearer.
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