Chronic cannabis use, whether smoked or eaten as edibles, significantly impairs blood vessel function — with risks mirroring those seen in tobacco smokers, according to UCSF researchers.
The study found that marijuana users had roughly 50% reduced vascular function compared to non-users, increasing their risk for heart attack and hypertension.
Chronic Cannabis Use Linked to Heart Risks
A new study from UC San Francisco has found that chronic cannabis use—whether smoked or eaten as edibles—may significantly harm your cardiovascular system.
Published May 28 in JAMA Cardiology, the research revealed that people who regularly used marijuana had much lower blood vessel function, similar to levels seen in tobacco smokers. In fact, vascular function in cannabis users was reduced by about 50% compared to non-users.
That matters because poor vascular function increases the risk of heart attacks, high blood pressure, and other cardiovascular problems.
Study Details: Who Was Studied and How
To uncover these effects, researchers studied 55 otherwise healthy adults between October 2021 and August 2024. All participants used cannabis regularly—at least three times per week for over a year—but did not use nicotine.
The participants either regularly smoked marijuana or consumed edibles containing tetrahydrocannabinol (THC), the primary psychoactive compound found in cannabis. On average, smokers had been using marijuana for about 10 years, while those who consumed edibles had used them for around 5 years.
Edibles vs. Smoking: A Surprising Distinction
Along with decreased vascular function, marijuana smokers had changes in their blood serum that were harmful to endothelial cells, which form the inner lining of all blood and lymphatic vessels. Those who took edibles containing THC, however, did not display these changes in blood serum.
It’s unclear how THC damages blood vessels. But the researchers said it must be happening in a way that does not involve those changes to blood serum.
These results suggest smoking marijuana negatively affects vascular function for different reasons than ingesting THC does, according to first author Leila Mohammadi, MD, PhD, and senior author Matthew L. Springer, PhD.
Reference: “Association of Endothelial Dysfunction With Chronic Marijuana Smoking and THC-Edible Use” by Leila Mohammadi, Mina Navabzadeh, Nerea Jiménez-Téllez, Daniel D. Han, Emma Reagan, Jordan Naughton, Lylybell Y. Zhou, Rahul Almeida, Leslie M. Castaneda, Shadi A. Abdelaal, Kathryn S. Park, Keith Uyemura, Christian P. Cheung, Mehmet Nur Onder, Natasha Goyal, Poonam Rao, Judith Hellman, Jing Cheng, Joseph C. Wu, Gregory M. Marcus and Matthew L. Springer, 28 May 2025, JAMA Cardiology.
DOI: 10.1001/jamacardio.2025.1399
Additional UCSF co-authors include Mina Navabzadeh, PharmD, Daniel D. Han, Emma Reagan, Jordan Naughton, Lylybell Y. Zhou, Rahul Almeida, Leslie M. Casteneda, Shadi A. Abdelaal, MD, Kathryn S. Park, Keith Uyemura, Christian P. Cheung, MSc, Mehmet Nur Onder, Natasha Goyal, MD, Poonam Rao, MD, and Gregory M. Marcus, MD, MAS.
The research was supported by grants from the National Institute on Drug Abuse (R01DA058069), the California Department of Cannabis Control (RG-1603151328-913), the California Tobacco-Related Disease Program (27IR-0012), the National Heart, Lung, and Blood Institute and the FDA Center for Tobacco Products (U54HL120163). Additional support came from the Elfenworks Foundation (in memory of Deb O’Keefe), the Roy E. Thomas Medical Foundation, and the Gootter-Jensen Foundation.
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6 Comments
How nice to know in 1974 my family doctor told me the same thing he was reaching out to all the students of my age he had lost someone for this.
Dr. Irvin Stein. RIP
Oh, another “Pot is dangerous” study. But a comparison to Alcohol is never forthcoming, neither is the horrendous damage to people and families from insanely punitive jail sentences…that do noting.
I don’t smoke or drink or use pot…but it should be legal everywhere.
its not even saying weed, should be illegal, its saying it can cause health problem, that could be something to be aware of like any other addictive substance, like alcohol or cigarettes.
it’s a cross sectional study that only found a correlation, not causation.
This is a cross sectional study. for those unfamiliar with the concept. cross sectional studies only tell you when A and B exist at the same time. not whether if A caused B or vice versa. just that they exist at the same time, also, conflict of interest in the study: FDA grants, CDCC grant, and similar ‘anti smoking’ organisation grants.
i don’t even smoke weed or cigarettes. i just don’t like when information that was inconclusive whether if smoking directly causes endothelial dysfunction is posted as ”weed could be wrecking your heart”. okay, where did the author reach this conclusion from? cross sectional studies are conducted at a single point in time. no before or afters. causation? good luck finding that out with a cross sectional study. depth? limited because data is collected at a single point in time. in the controlled variables of this study, lifestyle confounders were not eliminated. diet? sleep? stress? family history of any respiratory / cardiac conditions? it cannot provide any insight about risk progression or long term health outcomes.
in the abstract, “This cross-sectional study found that chronic cannabis smoking and THC ingestion were associated with endothelial dysfunction…”
the rersearchers used the word “associated” like responsible scientists. The article uses it like a blunt weapon.
also, you don’t know which came first in this study. endothelial dysfunction or smoking? yes they have been smoking regularly over the years. no this study on its own still isn’t enough to conclude that “weed made them experience endothelial dysfunction”. if it was further explored, sure, but in this case, nope. sorry.
this whole article is a reach. “weed could be wrecking your heart”. Dude, you literally wrote “The study found that marijuana users had roughly 50% reduced vascular function…”. This is NOT in the study. Study says “FMD drop from ~10% to ~4.6–6%” and in what world does “ FMD drop from ~10% to ~4.6–6%” = “50% reduced function” in total vascular capacity? It’s a measurement delta, not a physiological death sentence. That’s like saying someone is “50% less intelligent” because their test score dropped 10 points. Misleading.
Also, implying edibles are damaging when the study only shows blood serum affects only smokers? Ignoring the conflict of interest in the study? This is a clinically severe case of:
-Science:
Cross-sectional data shows cannabis might impair vascular function via different mechanisms depending on method of use. More research needed.
– Media:
“WEED = INSTANT HEART DISEASE 💀💀💀”
Whereas in reality, these findings could inform further cohort studies but right now, it is just correlation. this news article you wrote took correlation and turned into causation for clickbait. A simple correlation. Not a fact.
They should test me, I’m 46, been smoking weed for 34 years. My blood pressure has always been perfect, my heart and lung functions are perfect and I can still run or skate over 20 miles every day. My doctor says I’m an outlier but that’s even more reason to test people like me.