Cannabis Conundrum: Smoking or Eating THC Linked to Heart Disease Risk, Study Warns

A new study from UC San Francisco has dropped a bombshell for cannabis enthusiasts: whether you’re puffing on a joint or popping THC-laced gummies, your heart might be taking a hit. Published in JAMA Cardiology on May 28, 2025, the research links long-term cannabis use—smoked or eaten—to a heightened risk of heart disease due to impaired blood vessel function.

The study zeroed in on 55 outwardly healthy adults, aged 18 to 50, split into three groups: regular marijuana smokers, edible consumers, and non-users. Smokers averaged a decade of use, while edible fans clocked about five years. Tests conducted in September 2024 revealed that cannabis users had roughly half the blood vessel function of non-users, a red flag for risks like heart attacks and high blood pressure.

Smoking weed, it turns out, also messes with the blood serum, damaging cells lining blood and lymphatic vessels—something edibles didn’t do. Researchers noted that while both methods harm vascular health, they likely do so through different pathways. “It’s like your blood vessels are stuck in traffic, whether you’re inhaling or ingesting,” the study suggests, comparing the effects to tobacco smoking.

Dr. Bradley Serwer, a Maryland cardiologist not involved in the study, wasn’t shocked. “We’ve known THC can be trouble,” he told WTFNewsRoom. He cautioned that while cannabis has therapeutic uses, its chronic use isn’t harmless. The study’s small size—only 55 participants from the San Francisco Bay area—and reliance on self-reported data raise some questions, but the core finding stands: cannabis use could spell trouble for your ticker.

So, next time you’re eyeing that gummy or joint, maybe consider a heart-healthy hike instead. Your arteries might thank you.