The conversation about marijuana's health effects is expanding beyond its psychoactive properties and potential for dependency. The latest research brings cardiovascular health to the forefront of concerns. Recent studies point towards a significant association between cannabis use and a range of heart and blood vessel problems, regardless of whether the marijuana is smoked or ingested.
A new article in the journal Heart performed a systematic review and meta-analysis of studies published between January 1, 2016 and January 31, 2023 that reported risk estimates for cannabis-related major adverse cardiovascular events (MACE), such as cardiovascular death, non-fatal acute coronary syndrome (ACS) including myocardial infarction (MI), or non-fatal stroke. ACS refers to a group of sudden, reduced blood flow conditions affecting the heart that do not result in immediate death, ranging from non-fatal heart attacks to unstable angina, which is chest pain or discomfort due to inadequate blood flow to the heart muscles that can progress to a heart attack.
Combining data from multiple studies, the researchers found that that cannabis users had a 29% higher risk of acute coronary syndrome (pooled risk ratio RR =1.29), and a 20% increased risk of stroke (RR = 1.20). Examining only cohort studies, the increased risk for MACE was about 32% (Figure 1). The overall mortality risk (i.e. dying from cardiovascular disease) was two-fold higher (RR = 2.10) in those who consumed cannabis.
Two new studies presented at the American College of Cardiology's Annual Scientific Session in 2025 and published in JACC Advances (link) echoed these concerns, finding that cannabis users had a four-fold increased risk of ischemic stroke and a three-fold increased risk of a major adverse cardiovascular event (MACE). These numbers are higher than the data from the meta-analysis described in the previous paragraph perhaps because the subjects were younger with a lower control risk.
Indeed, a particularly disturbing trend is the vulnerability of younger adults. One retrospective study of over 4.6 million people found that cannabis users under the age of 50 were more than six times as likely to have a heart attack as their non-using peers. In addition, some of the studies in the Heart analysis also included a younger demographic, with participants typically aged between 19 and 59. This evidence suggests that marijuana use can significantly accelerate cardiovascular risk, placing even young, seemingly healthy individuals in danger.
Interestingly, a recent study from UCSF suggested that the mode of consumption may not matter, whether inhaled or ingested, which is somewhat surprising. Smoking was the primary method of consumption for approximately 75% of marijuana users in the study. Cannabis smoke contains many of the same harmful chemicals and toxins as tobacco smoke, which are known to contribute to heart disease. The act of smoking cannabis (or tobacco) creates a complex cocktail of toxins, fine particulate matter, and other combustion byproducts. When inhaled, these substances induce systemic inflammation and oxidative stress in the blood vessel endothelial lining.
Researchers found that found that regular users, whether they smoked cannabis or consumed edibles, showed a roughly 50% reduction in blood vessel function—a level of impairment comparable to that of tobacco smokers. This suggests that the mechanism of action of cannabis use on the cardiovascular system may be through tetrahydrocannabinol (THC), the primary psychoactive component.
These new findings appear in a landscape of marijuana use that has changed dramatically in recent years. Legalization for both medicinal and recreational purposes has not only increased its accessibility but has also likely softened public perception of its risks. This shift in attitude has corresponded with a rise in the drug's popularity. Compounding this issue is the significant increase in the potency of available cannabis products. This combination of more widespread use and stronger products may be a key factor behind the escalating cardiovascular risks now being identified by researchers.
The authors of an editorial accompanying the study in Heart advocate for treating cannabis with the same public health seriousness as tobacco. The recommendation is not to criminalize the drug, but to actively discourage its use through public awareness campaigns and to implement measures to protect non-users from the potential harms of secondhand vapor.
In summary, recent research has challenged the perception of marijuana as a safe drug. Evidence now links cannabis use to a significantly higher risk of heart attack, stroke, and death from cardiovascular disease, even among young adults. Studies show that both smoking and ingesting marijuana can impair blood vessel function, with some research indicating that the risk of a heart attack could be six times higher for users under 50. In light of these findings, which are amplified by the drug's increasing potency and accessibility, health experts are calling for a major public health re-evaluation. While the link to cardiovascular harm has been established, the precise mechanisms are still being explored. Further studies are essential to understand the long-term effects of different forms of consumption, such as edibles and vaping, to provide the public with a complete and accurate picture of the risks involved.
Figure 1. Forest plot of the association between cannabis use and MACE (major adverse
cardiovascular events) from cohort studies only. The odds ratio is shown along with the confidence interval (CI) in the right column. Some studies possessed large error bars which is reflected in reduced weighting for the calculation of the overall odds ratio, which was 1.32 (Storck et al. Heart, 2025).
No comments:
Post a Comment