New research suggests that clinicians should warn patients about the potential cardiovascular risks of cannabis use, though the extent of the risk depends on the amount used. A 2024 U.S. study of over 430,000 respondents found that daily cannabis users had a 49% increased risk of heart attack and a twofold increased risk of stroke. Even weekly users showed a slight increase in risk. Similar findings were observed in a 2022 Stanford study using UK Biobank data.
Cannabis may contribute to cardiovascular disease through various mechanisms. THC, the psychoactive component, binds to CB1 receptors in the heart and blood vessels, promoting atherosclerosis, inflammation, and oxidative stress. It may also have a prothrombotic effect, increasing the risk of heart attacks and strokes. Studies have linked cannabis use to arrhythmias, particularly atrial fibrillation.