Weed increases risk of major health issue — even without smoking: ‘Boy does it screw up the public health messaging’

Your best bud might be breaking your heart.

Though many Americans believe daily marijuana use is safer than tobacco, a new study suggests it could increase your risk for some serious cardiovascular issues.

Worse yet, gummies, teas and tinctures appear to offer no advantage over lighting up when it comes to one critical factor for your heart health.

High stakes for your heart

The study from researchers at the University of California, San Francisco involved 55 outwardly healthy Bay Area residents who regularly smoked marijuana or consumed THC edibles.

None of the participants used nicotine, and all of them consumed cannabis at least three times a week for a year or more. Smokers averaged 10 years of chronic use; edible users, five.

Researchers found blood vessel function in regular cannabis users was about half that of non-users — putting them on par with tobacco smokers.

“We found that vascular function was reduced by 42% in marijuana smokers and by 56% in THC-edible users compared to nonusers,” Dr. Leila Mohammadi, lead author of the study, told CNN.

That surprised co-author Dr. Matthew Springer. Groups like the American Heart Association had previously suggested edibles might be less harmful to the heart.

“When I first saw the THC result, I said to Leila, ‘Scientifically, this THC result is really interesting but boy does it screw up the public health messaging,’” he told SFGATE.

Notably, researchers found that only marijuana smokers had harmful changes in their blood serum that negatively affected their endothelial cells.

These cells line the inside of blood and lymph vessels and help regulate blood flow.

Springer said this could mean smoking marijuana delivers a “double whammy” of damage to heart health.

The researchers emphasized that while their study indicates a strong association between chronic marijuana or THC use and vascular damage, it doesn’t definitively prove the link.

Still, it adds to mounting evidence that chronic cannabis use could be bad news for the heart. A 2024 study found daily marijuana use increase heart attack risk by 25% and stroke risk by 42%.

“The public (and the medical field) should view cannabis and THC itself as products that are not without health risks,” Springer told Newsweek. 

“THC seems to have some beneficial effects also, so there needs to be a balance between risk and benefit that is best decided with both eyes open,” he added. 

Research suggests that marijuana has the potential to ease chronic pain and reduce muscle spasms and stiffness linked to MS.

Cannabis products have also been shown to boost appetite in HIV/AIDS and cancer patients, and combat chemo-related nausea.

Other potential benefits include easing stress, alleviating PTSD symptoms and aiding sleep in some people.

Springer and Mohammadi are calling for longer, larger studies to pun down exactly how marijuana and THC affect heart health — and to find out if there’s a safe level of use.

The study comes as more Americans are using marijuana regularly than ever before.

While alcohol is still more widely used overall, heavy marijuana use beat out heavy drinking for the first time in 2022, according to Carnegie Mellon researchers.

That year, about 17.7 million Americans used cannabis daily or near-daily — compared to 14.7 million who drank that often. It marks a staggering 15-fold jump in chronic cannabis use since 1992.

Marijuana remains illegal federally, but 38 states and DC have legalized it for medical use. Of those, 24 states and DC have also cleared the way for adults 21 and over to use it recreationally.

The recent legalization efforts have sparked a boom in cannabis use. In 2024, 47% of Americans said they’d tried marijuana at least once — up from 34% in 1999, according to Gallup polling.