New UCSF Study Reveals Alarming Link Between Cannabis Use and Heart Health Risks
By Han TT – June 2025
As cannabis continues to gain legal and cultural traction across the U.S., a new study from UC San Francisco is sounding the alarm: regular cannabis use—whether through smoking or edibles—may significantly impair cardiovascular health.
While many embrace marijuana for its soothing effects or therapeutic reputation, researchers now caution that its impact on the heart may be more harmful than previously believed.
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 The Hidden Cost of a “Natural” High
With recreational use legal in 24 states and medical approval in 39, cannabis is more accessible than ever. But researchers say this normalization might obscure the risks that come with habitual use.
A groundbreaking study, published May 28 in JAMA Cardiology, takes a closer look at how chronic cannabis consumption affects blood vessels and long-term heart function.
The Study Design
The research examined 55 adults between the ages of 18 and 50, all of whom were non-smokers of tobacco and generally in good health. Participants were divided into three categories:
- Regular cannabis smokers (averaging 10 years of use)
- Edible users (averaging 5 years of use)
- Non-users (control group)
Researchers conducted a series of vascular health tests in late 2024 to evaluate endothelial function—the performance of the thin cell layer lining blood vessels—and arterial flexibility.
 Key Findings: Impaired Blood Vessel Function
The results revealed a troubling pattern: both smokers and edible users showed significant vascular dysfunction, even in the absence of any current symptoms. Blood vessel performance among cannabis users was nearly 50% worse than that of non-users, a decline on par with the effects of tobacco smoking.
Smokers, in particular, demonstrated altered blood chemistry that appeared to damage both blood and lymphatic vessels—suggesting that inhaled cannabis poses dual threats: from the smoke itself and from the THC compound.
 What the Science Says
According to the researchers:
“Chronic cannabis smoking and THC ingestion were associated with endothelial dysfunction—similar in outcome to tobacco-related damage, though likely through different biological pathways.”
The study further emphasized that cannabis is not a risk-free substance, especially when used habitually.
Expert Perspective
Dr. Bradley Serwer, cardiologist and Chief Medical Officer at VitalSolution, echoed the study’s implications in a recent interview:
“This adds clarity to what we’ve suspected for years—THC can quietly affect cardiovascular health. Users may feel fine, but these underlying changes are real and potentially dangerous.”
Bottom Line: Think Beyond the Buzz
This study is part of a growing body of research challenging the narrative of cannabis as a harmless wellness tool. Whether smoked or eaten, frequent cannabis use appears to carry significant risk to the heart and blood vessels.
Though more research is needed to pinpoint exact mechanisms, one takeaway is clear: using cannabis regularly is not without consequences. For users—and for healthcare providers—the data calls for informed discussions and thoughtful moderation.
So, before lighting up or reaching for that gummy, it’s worth asking:
Is the calm worth the potential cost to your heart?