Cannabis Use Linked to Higher Heart Disease and Stroke Risk in Preliminary Study

Cannabis use was associated with higher odds of cardiovascular disease and stroke in a preliminary study of nearly 500,000 U.S. adults. The results point to a possible heart risk tied to THC itself, regardless of whether people smoked cannabis or consumed it in another form. The study is observational, however, so it can’t show that cannabis caused the diagnoses.

The findings are due to be presented at the American Heart Association’s Scientific Sessions 2026. They add to a growing health question as cannabis use becomes more common: in 2024, one in six U.S. adults said they had used cannabis in the previous month, up from one in 10 in 2020.

What the survey found

Researchers analyzed survey responses collected through the U.S. Behavioral Risk Factor Surveillance System from 2020 to 2024. Participants reported their cannabis use and whether a doctor had diagnosed them with a heart condition. The analysis included jurisdictions that collected information about cannabis use.

Compared with people who reported no cannabis use, those using it one to five days per month had 23% higher odds of reporting a cardiovascular disease diagnosis. For people using cannabis 16 to 30 days per month, the odds were 21% higher.

The stroke figures didn’t rise in step with use frequency. People who used cannabis one to five days per month had 40% higher odds of reporting a stroke, while those using it 16 to 30 days per month had 25% higher odds. That uneven pattern makes the relationship harder to interpret; the survey doesn’t explain why the lower frequency group showed the larger association.

These are preliminary results, not yet peer-reviewed, and the study measured associations rather than cause and effect. Cardiologist Sirisha Vadali, M.D., says the findings align with other signals researchers are seeing, but they should be treated as an early warning for further study rather than proof that cannabis causes cardiovascular disease.

Why THC may matter across formats

The findings held across different ways of consuming cannabis, which shifts attention beyond smoke exposure. Vadali says THC, cannabis’s main active ingredient, interacts with cannabinoid receptors in the heart and blood vessels. That activity can increase heart rate and cause sharp changes in blood pressure.

THC may also reduce nitric oxide, which helps protect blood vessels by limiting inflammation and plaque buildup. Vadali says cannabis can make platelets more prone to clumping, potentially increasing the chance of a blockage. In some people, it may narrow blood vessels or trigger irregular rhythms such as atrial fibrillation, which is associated with stroke risk.

Cardiologist Travis Benzing, M.D., describes THC’s effect on the heart as similar to a burst of adrenaline. Edibles bring a separate practical concern: because their effects take longer to appear, people may consume more than they intended while waiting.

What users and clinicians should take from the findings

The results don’t establish that cannabis is more harmful than alcohol, or that one option is safer for the heart. Vadali says the substances affect the cardiovascular system differently, and the evidence on cannabis is still developing. Calling cannabis harmless because it’s a plant, or assuming a non-smoked form avoids heart effects, goes beyond what the current evidence supports.

Both cardiologists urge patients to tell their doctors about cannabis use, especially if they have high blood pressure, diabetes, atrial fibrillation, a personal history of heart problems, or a family history of heart disease. Benzing says younger people who feel healthy shouldn’t assume the discussion is irrelevant.

The immediate takeaway is measured: this study raises a credible question about cannabis and cardiovascular health, but it doesn’t settle it. More research will need to explain the uneven stroke findings and clarify how use relates to heart risk over time.