Recent research suggests a significant correlation between marijuana use and increased heart attack risks, particularly among younger adults.
Recent research suggests a significant correlation between marijuana use and increased heart attack risks, particularly among younger adults. Two large-scale studies, including a meta-analysis of over 75 million people, reveal that cannabis users under 50 could face a six times higher risk of heart attack compared to non-users.
Marijuana and Heart Health: New Studies Highlight Risks
Marijuana is now legal in many places, but is it truly safe? Two new studies add to growing evidence that cannabis users face a higher risk of heart attacks, even among young and otherwise healthy individuals. The findings come from a large-scale retrospective study of over 4.6 million people published on March 18 in JACC Advances and a meta-analysis of 12 previously published studies being presented at the American College of Cardiology’s Annual Scientific Session (ACC.25).
As marijuana use continues to rise across the United States, particularly in states where it is legal for recreational use, researchers are uncovering potential health concerns. The retrospective study found that cannabis users under 50 were more than six times as likely to experience a heart attack compared to non-users. Meanwhile, the meta-analysis, the largest pooled study on this topic to date, found that marijuana use was associated with a 50% higher risk of heart attacks.
Clinical Insights and Recommendations
“Asking about cannabis use should be part of clinicians’ workup to understand patients’ overall cardiovascular risk, similar to asking about smoking cigarettes,” said Ibrahim Kamel, MD, clinical instructor at the Boston University Chobanian & Avedisian School of Medicine and internal medicine resident at St. Elizabeth Medical Center in Boston and the study’s lead author. “At a policy level, a fair warning should be made so that the people who are consuming cannabis know that there are risks.”
Extensive Research Findings
Kamel and his team conducted the retrospective study using data from TriNetX, a global health research network that provides access to electronic medical records. Their findings indicate that over an average follow-up of over three years, cannabis users had more than a sixfold increased risk of heart attack, fourfold increased risk of ischemic stroke, twofold increased risk of heart failure, and threefold increased risk of cardiovascular death, heart attack, or stroke.
All study participants were younger than age 50 and free of significant cardiovascular comorbidities at baseline, with blood pressure and low-density lipoprotein (LDL) cholesterol levels within a healthy range and no diabetes, tobacco use, or prior coronary artery disease.
Meta-Analysis: Broadening the Understanding of Cannabis Impact
For the meta-analysis, the researchers pooled data from 12 previously published research studies that collectively included over 75 million people. The studies were rated as being of moderate to good quality in terms of methodology. Of the 12 studies, 10 were conducted in the United States, one in Canada, and one in India. Some of the studies did not include information about participants’ ages, but the average age was 41 years among those that did, suggesting that the pooled sample reflected a relatively young population.
Taken individually, seven of the studies found a significant positive association between cannabis use and heart attack incidence, while four showed no significant difference and one showed a slightly negative association. When the researchers pooled the data from all studies and analyzed it together, they found a significant positive association, with active cannabis users being 1.5 times as likely to suffer a heart attack compared with those who aren’t current users.
The Ongoing Debate: Interpreting Cannabis Studies with Caution
Cannabis use and heart attack incidence were assessed in a similar manner across the different studies. However, due to inconsistencies in the data available from each study, researchers were unable to account for several potential confounding factors including the duration and amount of cannabis use or the use of tobacco or other drugs.
“We should have some caution in interpreting the findings in that cannabis consumption is usually associated with other substances such as cocaine or other illicit drugs that are not accounted for,” Kamel said. “Patients should be forthcoming with their doctors and remember that we are their number one advocate and having the full story matters.”
Mechanisms and Limitations: Unpacking the Potential Cardiovascular Effects of Cannabis
While the mechanisms through which marijuana or its components may impact the cardiovascular system are not fully understood, the researchers hypothesize that it can affect heart rhythm regulation, heighten oxygen demand in the heart muscle, and contribute to endothelial dysfunction, which makes it harder for the blood vessels to relax and expand, and can interrupt blood flow. One of the studies included in the meta-analysis found that the risk of heart attack peaked about one hour after marijuana consumption.
Since both studies were limited by their retrospective nature and the meta-analysis was limited by the challenges inherent in pooling data from multiple studies, researchers said that additional prospective studies would help to confirm the findings and determine which groups may face the highest risk.
A previous study presented at the American College of Cardiology’s Annual Scientific Session in 2023 found that daily marijuana use was associated with an increased risk of developing coronary artery disease.
Reference: “Myocardial Infarction and Cardiovascular Risks Associated with Cannabis Use: A Multicenter Retrospective Study” by Ibrahim Kamel, MHA, Ahmed K. Mahmoud, Anu Radha Twayana, Ahmed M. Younes, Benjamin Horn, DO and Harold Dietzius, FACC, 18 March 2025, JACC: Advances.
DOI: 10.1016/j.jacadv.2025.101698
Kamel will present the study, “Risk of Myocardial Infarction in Cannabis Users: A Systematic Review and Meta-Analysis,” on Saturday, March 29, 2025, at 2:00 p.m. CT / 19:00 UTC in South Hall at the American College of Cardiology’s Annual Scientific Session (ACC.25).
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25 Comments
There is a contradiction here: “Two large-scale studies, including a meta-analysis of over 75 million people, reveal that cannabis users under 50 could face a six times higher risk of heart attack compared to non-users….The retrospective study found that cannabis users under 50 were more than six times as likely to experience a heart attack compared to non-users. Meanwhile, the meta-analysis, the largest pooled study on this topic to date, found that marijuana use was associated with a 50% higher risk of heart attacks.” Did the meta-analysis find 6 times higher risk (600%), or a 50% higher risk? It says both. Maybe the author was high at the time of writing this.
I do agree that cannabis use should be considered in medical exams along with tobacco and alcohol and other drug use. It is a powerful herb with many impacts on the body, positive and negative. But this article seems biased against cannabis as evident by the above error. And there is no indication of cannabis dosage each use, quality of the cannabis, frequency of use, method of smoking/consumption, and resulting munchies and all the bad food eaten while being a couch potato. Maybe the food is the problem, since we know how junk food can cause cardiovascular problems.
It may help resolve the seeming contradiction to parse e v e r y word and phrase in both before making the comparison.
Presuming just confidence intervals, as I have not read the actual study, which would help before making perjorative comments. 6x it’s probably the max, 0.5x probably the mean or median. Journalist taking for granted that readers understand how these stats are presented. Obviously not.
If we can attribute it to 6 being the top and 0.5 being the mean, then the confidence interval would include 0. The results would not be statistically significant, so I doubt we can attribute it to that.
Perhaps it’s not the cannabis itself, but more to do with how it gives them munchies for junk food.
Cannabis legalization has freed me from decades of heavy opioid use due to diabetic neuropathy in the feet. And arthritis of the spine. I’m not perfect but at least my feet aren’t on fire anymore and the inflammation around the spine is .such that it’s tolerable. .sooo please stop badmouthing cannabis. Sounds like a pill pushing agenda to me
These studies are impossible to interpret with the limited information provided in this article. Importantly, there is no information on the route of administration. It is likely that the cardiovascular risk associated with smoking cannabis is significantly higher than any risk presented by any of the oral or even vaporized routes given the known risks associated with inhaling combustion products of practically any substance. Not including these details makes this article look like biased clickbait.
There’s medical uses for it, but for lots of healthy people it’s also a gateway drug. Youth who use it are multiple times more likely to subsequently use other drugs. The more cannabis they use, the more likely they are to use other drugs.
Friends I remember from high school 20+ years ago that used cannabis the most, Googling their names now, I see their names in the news. For crimes.
Alcohol is THE number one “gateway drug,” but all the drunks with “authority” have no intention of banning it, of course.
Thank you!
Oh here we go again with the old worn out tropes. Gaterways are just an excuse for poor parenting.
I suspect those who’ve been MRNA vaccinated are at a particularly high risk. The whole Marijuana study is a cover for the damage cause by them. People have been smoking weed since the dark ages. There would have been a massive amount of unexplained deaths due to heart issues during the 60’s and 70’s in young people. But sure. Let’s go with “the paid for science”.
Just don’t forget; there was a reason the western world legalized marijuana use right before the plandemic.
Cannabis = “bad, very bad!”
mRNA liquid idols = “a gift from god, wonderful beyond measure, incapable of causing injury or death.”
Mr. Norris, it sounds like you might be part of the delusional crowd.
Without impugning the evident appearance of risk suggested by the study, the authors of this article should stop using the now widely-deprecated phrase “heart attack” in reporting. It sounds unprofessional in medical journalism, except within the most popular low-grade media.
I’ll retract that comment. It appears to be still widely enough used in professional circles.
Why can’t they just state the facts? how did the participants use the cannabis? Was it inhaled as smoke, or vapors or was it consumed? Major differences in those three possibilities, and not a mention about it. This only highlights that fact that medical studies are being done in an unscietific manner and are only anecdotal at best.
I would think there is a huge difference between smoking Marijuana and edibles. This article says nothing about the means of getting THC into the body.
Because they don’t like all cannabis use, and this is how they target everything they don’t like. What I would like to know is who paid for this malarkey.
I find this article to be slipshod for some of the same reasons other commentators have pointed out. For about a year and a half I have been taking cannabis in the form of chews nightly as a sleep aid. They contain a small amount of THC. Was this the kind of use included in this study?
This is dumb.
No mention of dosage. Either sloppy research or reporting.
More “expert” OPINION – not fact – that can be safely dismissed.
Drinking water is 100% associated with death: everyone who dies drank water.
“Patients should be forthcoming with their doctors and remember that we are their number one advocate and having the full story matters.”
Seriously? What century does this doctor live in? So my medical records can be used without my consent (see this study)? So my health information is available to every hacker in the world (security is hard; especially for a business focused on people, not computers)? Where was my number one advocate when an experimental genetic treatment was misrepresented as a “vaccine” and inflicted on the population? Perhaps he was busy with the urgent health issues of racism and gun ownership.
I trust my doctor well enough. I do not trust the system in which my doctor works.
No one can reasonably make any assumptions at all about marijuana and health from this flawed set of reports! It was not controlled for cannabinoid dose, age (the ages of some of the subjects were unknown), route of administration (edible, smoked, vaped, etc.), diet, BMI, other comorbidities or risk factors like obesity, asthma/COPD, diabetes, etc. or consumption of other toxic substances or drugs (like alcohol, tobacco/nicotine, cocaine, methamphetamine, kratom, various synthetic cannabinoids, etc.). The very limited value it may have is associative only, but that value is largely diminished by the lack of adequate controls. Also positive, potentially protective factors like levels of exercise, physical activity, sleep and other positive lifestyle factors were apparently not controlled for either.
Reports of this kind of low quality “research” actually do more harm than good and reveal the obvious anti-cannabis bias of the study researchers and of the article reporter(s).