A heart attack risk six times higher than normal is not a small warning — it is a siren, and new research says marijuana users under 50 may be hearing it.
Quick Take
- A study of more than 4.6 million people found cannabis users under 50 had far higher rates of heart attack, stroke, and heart failure.
- Researchers reported a six-fold higher heart attack rate among users, even after excluding people with diabetes, high blood pressure, or tobacco use.
- A separate study of older military veterans with existing heart disease found no clear link between recent cannabis smoking and heart events.
- The American Heart Association has flagged real limits in this kind of research, including self-reported use and no data on potency.
A Massive Study Found A Troubling Pattern
Doctors led by Ibrahim Kamel pulled medical records on more than 4.6 million people, including 93,267 cannabis users, and published the results in JACC: Advances. Among users, 0.558% suffered a heart attack, compared to just 0.09% of nonusers. That works out to a risk ratio over six times higher.
The same analysis found cannabis users faced roughly four times the risk of ischemic stroke and twice the risk of heart failure. Researchers tried to strip out other explanations by focusing on people under 50 without diabetes, high blood pressure, coronary disease, or tobacco use, aiming to isolate marijuana’s role.
A separate pooled analysis of 12 earlier studies, cited by the American College of Cardiology, found a 50% higher heart attack risk tied to cannabis use. That is a smaller jump than the Kamel study’s headline number, but it points the same direction.
Big Percentages, Small Baseline Numbers
Here is the catch readers deserve to understand. A “six-fold” increase sounds like a near-certainty of disaster. But the actual gap between users and nonusers was 0.468 percentage points. Heart attacks are still rare events in people under 50, cannabis or not. The relative risk is real and worth taking seriously, but it is not the same as a coin flip.
The study also leaves real gaps. It does not say whether people smoked daily or just a few times a month, whether they used edibles or vapes instead of smoking, or how strong the product was. Those missing details matter if the goal is figuring out whether occasional use carries the same risk as heavy, daily use.
Not Every Study Points The Same Direction
A 2025 study in Circulation looked at older military veterans who already had coronary artery disease. Researchers tracked whether recent cannabis smoking predicted heart attacks, strokes, or cardiovascular death. It found no independent link, with an adjusted risk ratio of 0.87 — statistically no different from no effect at all.
The American Heart Association has raised its own concerns about this research field generally, including studies that rely on people accurately remembering and reporting their own drug use. It has also noted that most studies never measure how potent the cannabis product actually was, which makes comparing “users” to “nonusers” messier than it sounds.
A study of nearly 450,000 American adults links cannabis use to a significantly higher risk of stroke and cardiovascular disease. Whether participants smoked, vaped, or consumed edibles like gummies, the risk remained consistent. Casual users showed 40% higher odds of a reported… pic.twitter.com/KUwa42Rhn4
— Fox News Health (@foxnewshealth) November 6, 2026
What This Means For Weekend Users
None of this proves a joint or two a month will give someone a heart attack. But it also should end the idea that occasional cannabis use is automatically harmless just because it is legal in many states and increasingly normalized in daily life. The honest, common-sense reading is that cannabis carries real cardiovascular risk for some people, the size of that risk is still being mapped, and anyone with existing heart risk factors should treat it the way they would treat any other stimulant to the cardiovascular system — with real caution, not a shrug.
Sources:
facebook.com, acc.org, aha.org, pubmed.ncbi.nlm.nih.gov
