Last Monday, 28-year-old wellness coach Ava Martinez popped a single cannabis gummy before her evening jog. Within minutes, she felt severe chest tightness and dizziness—symptoms she’d never experienced. At the ER, doctors diagnosed her with endothelial dysfunction, a precursor to cardiovascular disease, despite her being a non-smoker. Her experience aligns with a new University of California, San Francisco study showing that both smoked marijuana and THC edibles impair blood-vessel health, raising the specter of heart attacks and strokes NBC News.
Researchers enrolled 60 healthy adults (ages 18–50), dividing them into three groups: daily marijuana smokers, regular edible users (primarily gummies), and a control group of nonusers. Using ultrasound to measure flow-mediated dilation (FMD)—an indicator of vessel elasticity—investigators found a 45 percent drop in FMD among smokers and a 58 percent drop among edible users compared to controls. Lead author Dr. Matthew Springer warned, “THC itself—whether inhaled or ingested—appears to acutely compromise vascular function” JAMA Network.
In addition to FMD measurements, the study tracked nitric oxide (NO) levels, crucial for vessel dilation. Smokers exhibited a 38 percent NO reduction post-consumption, while edible users showed unchanged NO but elevated inflammatory markers like C-reactive protein (CRP). “This suggests oxidative stress from smoke and inflammation from THC both undermine vascular health via distinct pathways,” noted co-author Dr. Leila Mohammadi CDC Heart Disease Info.
The research arrives amid rising cannabis legalization; over 37 million Americans now use marijuana regularly, with edibles representing one of the fastest-growing segments. A 2024 National Institutes of Health report found that 44 percent of users prefer edibles for “discreet consumption,” often unaware of delayed onset and dosing unpredictability NIH Cannabis Report.
Critics question the study’s limited sample size and reliance on self-reported usage. “We didn’t control for diet, exercise, or stress—key factors in vascular health,” cautioned cardiologist Dr. Benjamin Caplan in a CNN interview. Still, many public-health experts see the findings as a call to action. “With skyrocketing edible sales—marketed largely without health warnings—our duty is to inform consumers,” argued Dr. Lin.
Within hours of publication, social media erupted under #CannabisHeartRisk. On Reddit’s r/healthnews, users debated whether medical marijuana prescriptions should mandate cardiovascular screening. “Edibles are a ticking time bomb,” urged u/GreenLeafMom, while u/420Expert fired back, “Let’s see bigger cohorts before panicking.”
Legislators are already reacting. Senator Maria Cantwell (D-WA) announced a hearing to review edible labeling standards. “We need explicit cardiovascular warnings on packaging,” she stated. The proposed Heart Health and Cannabis Safety Act would require clear risk disclosures and fund clinics for early heart screenings among frequent users.
Meanwhile, the FDA is reportedly considering new guidelines requiring THC concentration limits and standardized dosing units for edibles. Consumer advocacy group Consumer Reports has launched a petition demanding updated federal regulations, arguing that “19 states regulate cannabis, but edible oversight remains patchy.”
At the local level, emergency departments are already noting changes. Dr. Caleb Ward, an ER physician at Cedars-Sinai, reports a 12 percent increase in cannabis-related cardiac cases over the past year. “We see more young adults with palpitations and chest pain after consuming THC products,” he said in a Fox News Health segment. “Patients often dismiss ‘just a gummy’ as harmless.”
Consumer behavior may shift as a result. Dispensaries in Colorado and California are reportedly updating educational materials to include heart-risk advisories. Recreational user Marcus Lee, 30, says he’s rethinking his routine: “I’ll still vape occasionally, but I’m cutting down on edibles until we know more.”
The UCSF team acknowledges limitations: small cohort, regional focus, and short-term measurements. They call for larger, longitudinal studies to assess long-term cardiovascular outcomes. “We’ve only scratched the surface,” Dr. Springer notes. “But for now, if you use cannabis—especially edibles—get your heart checked regularly.”
As policy debates heat up, patients like Ava Martinez serve as living reminders that perceived “harmless” cannabis can carry hidden dangers. “I thought I was choosing a healthier option,” Ava says. “Now I know my heart demands respect. And I’ll never take it for granted.”
