As marijuana becomes legal in more places, new research raises concerns about its impact on heart health—even in young, otherwise healthy individuals. Two recent studies presented at the American College of Cardiology’s 2025 Annual Scientific Session found that cannabis users under 50 were significantly more likely to experience heart attacks, strokes, heart failure, and cardiovascular-related deaths compared to non-users. One retrospective study involving over 4.6 million people revealed a sixfold increase in heart attack risk and a fourfold increase in stroke risk among cannabis users. A separate meta-analysis of 12 studies, covering over 75 million participants, showed cannabis users were 50% more likely to have a heart attack. Notably, the studies focused on individuals without existing cardiovascular conditions, diabetes, or tobacco use, suggesting cannabis may independently contribute to cardiovascular risks.
Key Facts:
- Marijuana users under 50 were 6x more likely to have a heart attack.
- Cannabis use linked to 4x higher risk of stroke and 2x higher risk of heart failure.
- Meta-analysis of 75+ million people found a 50% increased risk of heart attack in users.
- Cannabis may affect heart rhythm, increase oxygen demand, and impair blood vessel function.
- Risk of heart attack appears highest within 1 hour after marijuana use.
While cannabis is increasingly viewed as safe due to its legal status, these studies emphasize the need for caution—especially among younger adults who may underestimate its risks. Clinicians are now encouraged to include cannabis use when assessing cardiovascular health. Further research is needed, but the existing evidence is strong enough to warrant public health warnings and more informed conversations between patients and providers. Legal doesn’t always mean harmless, and understanding the risks is key to protecting your heart.
