Chamba Chitha Kukoma — But Not for Your Heart, Says Science.
Let’s face it, marijuana has gotten itself quite the wellness glow-up over the past few years. With dispensaries looking more like Apple stores and edibles coming in fancy boxes that scream “self-care,” it’s easy to believe cannabis is all peace, love, and plant-based healing. After all, it’s natural, right? Organic even. What could possibly go wrong?
Well, according to science — and your arteries — maybe a little more than you’d think.
Researchers at the University of California, San Francisco, decided to check in with the unsung heroes of your body: your blood vessels. Specifically, they wanted to see how cannabis use affects vascular function — that’s science-speak for how well your arteries can widen to let blood flow freely. Spoiler alert: they weren’t throwing a party.
In a small but eyebrow-raising study, they looked at 55 adults between 18 and 50 years old. Some were regular cannabis users — either smoking weed or indulging in THC-laced edibles at least three times a week for a year. The rest were cannabis-free, clean as a Whole30 grocery list. No tobacco, no vapes, and barely any secondhand smoke to blame anything on. This was a fair fight.
Using an ultrasound, the researchers tested how the arteries in participants’ arms responded after being temporarily squeezed off with a cuff for five minutes. (Basically, a stress test for your blood flow. Super casual.) And the results? Not great, Bob.
They found that vascular function — the ability of arteries to expand when they need to — was reduced by 42% in marijuana smokers. Edible users did even worse, with a 56% reduction. Yes, you read that right: eating your weed might mess with your blood vessels more than smoking it. Someone tell the “it’s just a brownie” crowd.
None of these folks had blocked arteries or plaque buildup, but their blood vessels simply weren’t doing their thing — widening when they should. And that, according to researchers, is a red flag for future heart problems like strokes, heart attacks, and generally cranky cardiovascular systems.
But wait, there’s more. The researchers also ran lab tests and found that blood from marijuana smokers caused the cells lining blood vessels to release 27% less nitric oxide. That’s the stuff that tells your arteries, “Hey, relax, open up, let the blood flow!” So less nitric oxide means tighter, less cooperative blood vessels. And that’s bad news for your ticker. For comparison, tobacco smokers showed a 39% drop in nitric oxide — so marijuana isn’t exactly the innocent cousin in this story.
Interestingly, blood from edible users didn’t cause the same nitric oxide drop in the lab tests, which suggests that the THC might mess with your arteries in different ways depending on how you consume it. Either way, your blood vessels are like, “Ugh, here we go again.”
Dr. Matthew Springer, one of the lead researchers, summed it up like this: “You do yourself no favors by switching from tobacco to marijuana. Smoking marijuana just gives you a double hit — the smoke and the THC.” So all those folks who proudly ditched cigarettes for joints? Your heart may not be as impressed as you are.
The American Heart Association agrees. They recommend avoiding smoking or vaping any substance, including cannabis. Their 2020 guidance even warned that irregular heart rhythms — like atrial fibrillation — can pop up within an hour of smoking THC. Yep, that relaxed high might come with a side of “Why is my heart doing jazz hands?”
Of course, more research is needed. The sample size was small, and scientists are still figuring out whether lower doses, different forms like tinctures or teas, or less frequent use might be safer. As one reviewing cardiologist put it, “There might be a Goldilocks zone for cannabis — not too much, not too little, just right.” But until we find that magical middle ground, your best bet might be not assuming weed is harmless just because it comes in a gummy bear.
So next time someone says, “Weed is way safer than tobacco,” you can smile and say, “Only if you don’t mind arteries that act like they just broke up with you.” Your heart deserves love too — and that might mean thinking twice before lighting up or diving face-first into a pan of infused brownies.
Because while cannabis might lift your mood, your blood vessels are just trying to survive the trip.
