Even occasional cannabis use was associated with higher odds of stroke and cardiovascular disease in a new study involving nearly 450,000 American adults. The findings suggest that the association may affect casual users as well as people who consume marijuana frequently.

The research is scheduled for presentation at the American Heart Association’s Scientific Sessions 2026 in Chicago from Nov. 6 through Nov. 9. The findings remain preliminary until they complete the full peer reviewed publication process.

Researchers examined survey responses collected from 2020 through 2024 using the Centers for Disease Control and Prevention's Behavioral Risk Factor Surveillance System. Participants reported information about cannabis use, medical diagnoses and their cardiovascular histories.

Adults who reported using cannabis between one and five days per month had 23% higher odds of reporting a history of cardiovascular disease compared with people who did not use it. Those who used cannabis 16 to 30 days per month had 21% higher odds.

The stroke figures were even more striking. People who used cannabis between one and five days per month had 40% higher odds of reporting a previous stroke, while those in the heavy use group had 25% higher odds.

Dr. Kristen "Nicke" Worth, an Ohio based physician and medical adviser at NuggMD, was not involved in the research. NuggMD is a telehealth platform for medical marijuana evaluations.

"One finding I found particularly interesting was that people who used cannabis just one to five days per month had somewhat higher reported odds of a previous stroke than people who used it more frequently," Worth told Fox News Digital.

That unexpected pattern did not mean heavier cannabis consumption was safer, Worth cautioned. "That isn't what we'd necessarily expect from a straightforward dose-response relationship, where greater exposure is associated with greater risk. But we shouldn't interpret this as evidence that heavier use is safer," Worth said.

The method of cannabis consumption did not change the outcome reported by the researchers. The association remained consistent whether participants smoked marijuana, vaped it or consumed edible products such as gummies.

Lead author Dr. Aabha Divya, an assistant professor of cardiothoracic surgery at Tulane University School of Medicine, said researchers had expected cardiovascular risk to rise gradually with more frequent cannabis use. Instead, both the low use and heavy use groups showed elevated odds of heart disease.

"We were surprised to find that the link between cannabis use and cardiovascular disease was not straightforward," Divya said in an American Heart Association press release. "We expected that the chances of heart disease would gradually rise as people used cannabis more often, but that wasn't the case. Both low-use and heavy-use groups had higher odds of developing heart disease."

Despite the association with stroke and overall cardiovascular disease, researchers found no statistically significant connection between cannabis use frequency and heart attacks. The study also reported that cannabis use had grown substantially during the period covered by the survey data.

About one in six adults reported using cannabis during the past month in 2024, compared with one in 10 adults in 2020. According to the research team, that represented a 51% increase over four years.

Dr. Robert L. Page II, a professor of clinical pharmacy at the University of Colorado and an American Heart Association volunteer expert, was not involved in the study. He said the findings challenge assumptions that cannabis is an innocent factor when patients also have other risks.

"Overall, cannabis is beginning to emerge as a major contributor to premature heart disease in young and older adults , which can lead to serious cardiovascular events," Page said. He also advised doctors to ask patients about marijuana use just as they ask about cigarettes and alcohol.

The study had several important limitations. Because it was observational and captured information from a single point in time, it could identify a statistical association but could not establish that cannabis caused cardiovascular disease or strokes.

The telephone survey data also depended on participants accurately remembering and reporting their drug use and medical diagnoses. Researchers did not track the strength of cannabis products, THC potency or the total amount each participant consumed.

Worth urged patients not to make sudden changes based on one preliminary study. "People should not discontinue prescribed cardiovascular medications because of this report."

"Anyone using cannabis, medically or recreationally, should discuss their cardiovascular history, existing risk factors, medications and treatment alternatives with their healthcare professional," Worth added. The findings offer a reason for both occasional and frequent users to make cannabis part of those conversations.