BOSTON — A recent study conducted by researchers at the University of California, San Francisco (UCSF), published on May 28, 2025, in JAMA Cardiology, has identified significant cardiovascular risks associated with chronic cannabis use. The study reveals that prolonged consumption of cannabis, whether through smoking or edibles, may impair blood vessel function, leading to increased chances of heart-related complications.
The research involved 55 healthy adults aged 18 to 50 who used cannabis at least three times a week for over a year. Participants were divided into two groups: those who smoked marijuana and those who consumed THC-infused edibles. Notably, none of the participants used tobacco or were exposed to secondhand smoke, ensuring that the observed effects were attributable to cannabis use alone.
Findings indicated that vascular function was reduced by approximately 42% in marijuana smokers and 56% in edible users compared to non-users. This level of impairment is comparable to that observed in tobacco smokers. Reduced vascular function is a known risk factor for heart attacks, hypertension, and other cardiovascular conditions.
Further analysis revealed that marijuana smokers exhibited harmful changes in their blood serum, adversely affecting endothelial cells that line blood vessels. These changes were not observed in edible users, suggesting that smoking cannabis introduces additional harmful substances beyond THC itself.
Dr. Leila Mohammadi, the study’s lead author, emphasized the significance of these findings: “We found that vascular function was reduced by 42% in marijuana smokers and by 56% in THC-edible users compared to nonusers.” Co-author Dr. Matthew Springer added, “The observations that marijuana smokers and THC users each have poor vascular function might make people conclude that the THC is responsible for all of … . But our data suggest that both THC and smoke contribute to vascular changes in different ways.”
This study adds to a growing body of evidence linking cannabis use to cardiovascular issues. A 2024 study found that daily marijuana use increases the risk of heart attack by 25% and stroke by 42%. Another study presented at the American College of Cardiology’s Annual Scientific Session in 2025 reported that cannabis users under 50 were over six times more likely to suffer … compared to non-users.
As cannabis legalization expands, with 38 states and Washington, D.C., permitting medical use and 24 states allowing recreational use, public health officials are urging for more comprehensive research to understand the full scope of cannabis’s effects on the cardiovascular system. Dr. Springer noted, “The public (and the medical field) should view cannabis and THC itself as products that are not … .”
Medical professionals recommend that individuals, especially those with existing heart conditions, consult healthcare providers before using cannabis. They also advocate for increased public awareness and informed consumption practices to mitigate potential health risks associated with chronic cannabis use.
