Smoking marijuana and eating cannabis gummies both linked to dangerous health risk, study finds

Fox News

2 days ago

Long-term cannabis use in any form has been linked to a greater risk of heart disease.
In a new study, researchers at UC San Francisco determined that eating edible cannabis, such as gummies, has the same impact on cardiovascular risk as smoking marijuana.
The risk stems from reduced blood vessel function, according to the study, which was published in JAMA Cardiology on May 28.
The study included 55 people between 18 and 50 years of age who were "outwardly healthy."
The participants were divided into three groups: those who regularly smoked marijuana, those who ate edibles containing THC (tetrahydrocannabinol), and those who didn't use cannabis, according to a UCSF press release.
The cannabis users had been consuming the substance at least three times weekly for at least one year.
On average, the smokers had the habit for 10 years, while those consuming edibles had been doing so for five years, the release noted.
In September 2024, the participants underwent testing to determine how well their blood vessels functioned and whether the cells lining the blood vessels were affected.
All cannabis users were found to have "decreased vascular function," comparable to those who smoke tobacco.
Their blood vessel function was roughly half compared to those who did not use cannabis.
This side effect has been linked to a higher risk of heart attack, high blood pressure and other cardiovascular conditions, the researchers noted.
The participants who smoked marijuana were also found to have changes in their blood serum that harmed cells lining their blood vessels and lymphatic vessels, an effect that was not seen in those who ate edible cannabis.
The researchers noted that while smoking marijuana and consuming edibles both affect vascular function, they likely do so for different reasons.
"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.
"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."
Dr. Bradley Serwer, a Maryland-based cardiologist and chief medical officer at VitalSolution, an Ingenovis Health company that offers cardiovascular and anesthesiology services to hospitals nationwide, said he was not surprised by the study's findings.
"We have known that the chronic use of THC-containing compounds can have negative health consequences — this study just reaffirms those prior studies," Serwer, who was not involved in the UCSF research, told Fox News Digital.
The study did have some limitations.
"Variability in cannabis strains complicates standardization," the researchers wrote. "Self-reported cannabis use may introduce recall bias; thus, participants were queried at multiple points: in the online survey, at the eligibility interview and before each visit."
It was also challenging to determine whether blood vessel function could have also been affected by lifestyle factors like stress, caffeine and secondhand smoke exposure, they noted.
Serwer pointed out that this was a "very small" study of only 55 people, all living in the San Francisco Bay area.
"The decision to use or avoid it should be made with all benefits and risks in mind."
"The study did not allow for variability in the different strains of cannabis, and they used a self-reporting survey, which can be under- or over-reported," he told Fox News Digital.
"They looked for physiologic endpoints and not hard endpoints, such as heart attacks, strokes or death. We have to infer that the physiologic endpoints would result in cardiovascular events."
The cardiologist said he agreed, however, with the conclusion that cannabis use is "not benign."
"Chronic use does have potential cardiovascular risks," he warned. "There are therapeutic uses of cannabis, and the decision to use or avoid it should be made with all benefits and risks in mind."
In general, Serwer said he cautions all of his patients to avoid any unnecessary cardiac risks.
"As clinicians, we must weigh the benefits and the risks of a medicine/drug or intervention," he said. "If the risks outweigh the benefits, it should be avoided."
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The study was funded mainly by the National Institute on Drug Abuse; the California Department of Cannabis Control; the California Tobacco-Related Disease Program; the National Heart, Lung, and Blood Institute; and the FDA Center for Tobacco Products.
Fox News Digital reached out to cannabis industry organizations requesting comment.