In a season when cannabis is becoming ordinary across American life, a large survey of nearly half a million adults has offered a quiet but unsettling observation: those who used marijuana even a few days a month were more likely to report a past stroke than those who never used it. The finding, presented in Chicago by researchers from Tulane, does not prove that the plant harms the brain or the heart, since a single snapshot in time cannot reveal which came first. Yet it arrives at a moment when many people and their doctors have assumed that occasional use is benign, and it asks whether that
Occasional Marijuana Use Linked to 40% Higher Odds of Reported Stroke in Large US Survey
The risk did not climb in a neat line
Mark
The headline number is 40% higher odds of stroke for occasional users. Why does that surprise people?
Mimi
Because the researchers expected a staircase: more use, more risk. Instead the low-frequency group, 1 to 5 days a month, showed 40% higher odds, and the heaviest group showed 25%.
Mark
So what does that say about the heaviest users?
Mimi
Divya said both low-use and heavy-use groups had higher odds, but the pattern wasn't straightforward.
Luke
I'd stop on the word odds. These are odds of reporting a past stroke diagnosis, not a measured rate of strokes among users.
Mark
And it's all self-reported?
Luke
Yes, by phone, from memory, for both cannabis use and diagnoses. And it's a single snapshot, so we can't tell what came first.
Mimi
There's a twist on that. Some people may have stopped using after a diagnosis, so the no-use group may include former users.
Luke
Which could distort the comparison, though the study can't say in which direction or by how much.
Mark
What about tobacco, which is a known risk?
Mimi
They adjusted for it. Page, an outside expert, still says tobacco co-use clouds this whole field, though he called this the second observational study pointing to cannabis alone.
Luke
Note that's his reading. Adjusting statistically isn't the same as proving cannabis is the cause, and there's no data on potency or dose.
Mark
So what's the takeaway?
Mimi
Talk about cannabis with clinicians the way you would tobacco and alcohol. That's the practical ask, and it doesn't depend on settling causation.
O Pulso
- A finding that contradicted the researchers' own expectation has unsettled assumptions about occasional cannabis use.
- Stroke stands out as the sharpest signal, with odds 40% higher among low-frequency users, while heart attack shows no clear link.
- Cannabis use has surged, rising from 1 in 10 adults in 2020 to 1 in 6 in 2024, widening the population at stake.
- Tobacco co-use and self-reported data muddy the picture, leaving researchers unable to confirm causation.
- Clinicians are being urged to screen cannabis use in heart-health visits as they would tobacco, while longitudinal studies are still needed.
In a season when cannabis is becoming ordinary across American life, a large survey of nearly half a million adults has offered a quiet but unsettling observation: those who used marijuana even a few days a month were more likely to report a past stroke than those who never used it. The finding, presented in Chicago by researchers from Tulane, does not prove that the plant harms the brain or the heart, since a single snapshot in time cannot reveal which came first. Yet it arrives at a moment when many people and their doctors have assumed that occasional use is benign, and it asks whether that assumption deserves the same scrutiny once given to tobacco.
At the American Heart Association's Scientific Sessions in Chicago, researchers reported a result they had not anticipated: adults who used marijuana just a few days a month were more likely to report having had a stroke than adults who never used it, with odds about 40% higher. The team, led by Aabha Divya of Tulane University, drew on 442,906 American adults surveyed between 2020 and 2024 through a large telephone health survey. Participants reported how often they had used cannabis in the past month, and whether a doctor had ever diagnosed them with heart disease, heart attack, or stroke. The analysis accounted for age, tobacco, alcohol, weight, diabetes, kidney disease, activity, education, and income.
The pattern was not a simple slope. Heavier use did not produce steadily greater risk; low-frequency users showed a notable cardiovascular signal, and heavy users did too, though less strongly. Heart attack showed no significant link at all. Divya pointed to how quickly cannabis use has grown, noting that roughly one in six American adults reported using it in 2024, up from one in ten in 2020, and argued that patients and clinicians should talk about it as they talk about tobacco and alcohol.
Outside experts urged caution in both directions. Robert L. Page II, who was not involved in the study, observed that many cannabis users also smoke tobacco, which complicates any conclusion, though he noted this is only the second observational study to suggest a risk from cannabis alone. The authors themselves acknowledge that a one-time survey cannot establish cause, that memories and self-reports may be imperfect, and that data on potency and amount were missing. For now, the result is a warning sign rather than a verdict, and the next step is research that follows people over years.
At the American Heart Association's Scientific Sessions in Chicago, which ran November 6 through 9, 2026, researchers presented a finding that cut against what they had expected to see: adults who used marijuana only a few days a month were more likely to report a history of stroke than adults who used none. The odds were 40% higher.
The work comes from a team led by Aabha Divya, an assistant professor in the division of cardiothoracic surgery at Tulane University School of Medicine in New Orleans. Her group analyzed 442,906 American adults, with an average age of 49 and roughly half of them women. All had answered the Behavioral Risk Factor Surveillance System, a large telephone survey, between 2020 and 2024. Only states that included an optional marijuana questionnaire were counted, somewhere between 16 and 24 per year, so the sample does not cover the whole country.
Participants said how many days in the previous month they had used cannabis, whether smoked, vaped or eaten as gummies or other foods. They were sorted into four groups: no use, low frequency (1 to 5 days), moderate (6 to 15 days) and heavy (16 to 30 days). They also said whether a health professional had ever diagnosed them with a heart attack, heart disease, heart-related chest pain or stroke. The researchers adjusted for demographics, tobacco smoking, alcohol, obesity, diabetes, chronic kidney disease, physical inactivity, education and income.
The results did not climb in a neat line. Adults using cannabis 1 to 5 days a month had 23% higher odds of reporting cardiovascular disease than non-users, while those using it 16 to 30 days had 21% higher odds. Stroke showed the strongest signal: 40% higher odds among low-frequency users and 25% among heavy users. For heart attack, the team found no statistically significant association with frequency of use. Divya said the group had expected risk to rise gradually with more frequent use, and that it did not.
Divya framed the work against rapid change. She cited earlier research showing that 1 in 6 US adults reported using cannabis in the past month in 2024, up from 1 in 10 in 2020, a 51% increase. Studies from 2016 to 2020 had already tied cannabis to poorer cardiovascular outcomes, but results were inconsistent, and legalization and commercial products have kept expanding. She argued that people and their clinicians should discuss cannabis the way they discuss tobacco and alcohol.
Robert L. Page II, a professor at the University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences who led the writing group for the AHA's 2020 cannabis scientific statement, was not involved in the study. He noted that many cannabis users also smoke tobacco, which clouds the question of cardiovascular risk. In people who use both, he said, cannabis has long been treated as an innocent bystander, and he called this the second observational study suggesting cannabis exposure without tobacco may be a risk factor. He said cannabis is emerging as a major contributor to premature heart disease in younger and older adults, and urged clinicians to address it as they would tobacco.
The study's limits are substantial, and the authors state them. The survey captured one moment, so it cannot show whether cannabis use came before the cardiovascular problem or contributed to it. Both cannabis use and medical history were self-reported and depend on memory. The survey had no data on product potency or quantity. And some people may have cut back or quit after a diagnosis, meaning the no-use group could include former users.
For now the finding is an association, not a verdict. The unanswered questions are whether the pattern holds in studies that follow people over time and whether potency and dose matter. Meanwhile, the researchers want cannabis on the list of things discussed in heart-health visits.
Citações Notáveis
We expected heart disease odds to rise gradually with more frequent use, but that wasn't the case; both low-use and heavy-use groups had higher odds.— Aabha Divya, Tulane University School of Medicine
Clinicians should address cannabis use with patients as they would tobacco use when considering cardiovascular risk.— Robert L. Page II, University of Colorado (not involved in the study)
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