Weed, edibles linked to increased heart disease risk, study finds

A new study from researchers at the University of California, San Francisco, has found that long-term cannabis use is associated with a higher risk of heart disease and reduced blood vessel function. The study noted that these risks occur regardless of whether marijuana is smoked or consumed as edibles.

Published Wednesday in JAMA Cardiology, the study examined 55 healthy individuals between the ages of 18 and 50, dividing them into groups based on cannabis use. One group regularly smoked marijuana, another consumed THC edibles, and a third group did not use cannabis at all. Cannabis users in the study had been consuming the drug at least three times per week for over a year, with smokers averaging 10 years of use and edible users about five.

In testing conducted in September 2024, researchers found that both groups of cannabis users had significantly reduced blood vessel function, with vascular performance measured at about half that of non-users. These side effects are associated with an increased risk of heart attack, high blood pressure, and other cardiovascular conditions. They are also similar to the risks observed in long-term tobacco smokers.

While edibles have been assumed to carry a reduced risk than smoking marijuana, the report found that edible users had a higher reduction in vascular functions.

"We found that vascular function was reduced by 42% in marijuana smokers and by 56% in THC-edible users compared to nonusers,” the lead author of the study, Dr. Leila Mohammadi, told CNN.

However, those who smoked marijuana showed harmful changes in their blood serum that negatively affected cells lining blood vessels, an effect not observed in those who consumed cannabis through edibles.

"Chronic cannabis smoking and THC ingestion were associated with endothelial dysfunction [impaired functioning of the endothelial cells lining the inside of blood vessels] similar to that observed in tobacco smokers, although apparently occurring via distinct mechanisms," the researchers wrote in their findings. "This study enhances the understanding of the potential risks to vascular health linked to cannabis use and provides more evidence that cannabis use is not benign.