As marijuana legalization spreads across the United States and other parts of the world, concerns about its safety are growing. Two recent studies have added to the growing evidence that cannabis use may significantly increase the risk of heart attacks, even among younger and otherwise healthy adults. Researchers published these findings in JACC Advances and presented them at the American College of Cardiology’s Annual Scientific Session (ACC.25) after conducting a retrospective analysis of roughly 4.6 million people.

Cannabis Use Linked to Increased Heart Attack Risk

The first study found that cannabis users under the age of 50 were more than six times as likely to suffer a heart attack compared to non-users. Researchers used data from TriNetX, a global health research network, to track cardiovascular outcomes over an average follow-up period of three years. The study revealed that cannabis users faced a 6 times greater risk of cardiovascular attacks, a 4 times increased risk of ischemic stroke, a 2 times greater likelihood of suffering heart failure, and a 3 times greater likelihood of becoming victims of cardiovascular death.

All participants in the study were under 50 years old and had no significant cardiovascular comorbidities at the time of conducting the study. They also had healthy blood pressure and cholesterol levels, no diabetes, and no history of tobacco use or coronary artery disease. Despite these favourable health profiles, the findings suggest that cannabis use alone may pose a significant threat to heart health.

The second study, a meta-analysis of 12 previously published research studies, pooled data from over 75 million people. This analysis, the largest of its kind to date, found that active cannabis users were 1.5 times more likely to suffer a heart attack compared to non-users. Seven of the 12 studies included in the meta-analysis showed a significant positive association between cannabis use and heart attack incidence, while four found no significant difference, and one showed a slightly negative association.