Regularly smoking weed or consuming edibles may raise the risk of suffering a heart attack, a study suggests.Â
The team from the University of California San Francisco who made the find warns it is ‘more evidence cannabis use is not benign.’
It also comes amid an alarming rise in unexplained heart attacks in young Americans, which experts are still trying to unpack.
Researchers discovered that individuals who smoked marijuana or consumed edibles at least three times a week experienced a reduction in blood vessel function by up to 52% compared to those who did not use cannabis.
And endothelial cells, which line the blood vessels, were less able to regulate blood flow and deliver crucial oxygen throughout the body.Â
This causes blood vessels to constrict, raising the risk of blood clots, which can lead to coronary artery disease, heart attacks and stroke. Â
The findings of the study add to existing research linking smoking cannabis to heart disease. This report stands out as one of the initial studies highlighting the potential heart damage associated with consuming THC-infused edibles.

The University of California San Francisco conducted the study, which underscores the negative impact of marijuana consumption on blood vessel function, consequently increasing the risk of a heart attack.
Matthew Springer, study co-author and professor of medicine at UCSF, told CNN: ‘We’re looking at a window in the future, showing the early changes that may explain why smoking marijuana has been linked to later heart disease.’
About 18million Americans use marijuana daily or nearly every day.Â
Cannabis use is also on the rise, largely due to recent decriminalization across the US. From 1992 to 2022, for example, daily and near-daily use has seen a 15-fold rise.Â
The study, published this week in JAMA Cardiology, recruited 55 healthy adults ages 18 to 50 who neither smoked tobacco nor vaped. They also were not regularly exposed to secondhand smoke.
They were then sorted into three groups based on chronic cannabis use: using marijuana three times per week for at least a year, consuming at least three THC edibles a week for a year or not using cannabis at all.Â
Cannabis users were 30 years old on average while nonusers were 28.Â
None of the participants had pre-existing heart conditions.
They found people who smoked marijuana or used edibles at least three times a week performed worse on tests measuring blood vessel function.
Marijuana smokers had a 42 percent reduction in vascular function than controls, while THC edible users had a 52 percent reduction compared to those who never used cannabis.Â
This was determined through heart scans.
Endothelial cells, which line the blood vessels and regulate blood flow, released less nitric oxide in people who regularly smoked marijuana or took edibles.
Nitric oxide helps blood vessels dilate and deliver vital oxygen throughout the body.
This impaired function causes blood vessels to constrict, increasing the risk of inflammation and blood clots, which can lead to heart disease and increase the risk of a heart attack. Â

Data shows that heart attack cases are on the rise in young Americans. The new study suggests marijuana could partly be to blame
Nearly 1million Americans every year die of cardiovascular disease, a group of conditions including coronary artery disease, heart attack and stroke.Â
It’s America’s leading cause of death, with cancer and accidental injuries following closest behind.Â
Because the average participant in the new study was 30 years old, the study could help explain why young Americans are increasingly suffering heart attacks.
Previous research has suggested the use of drugs like marijuana, as well as conditions like Covid and type 2 diabetes, may be to blame.Â
However, the researchers cautioned the study only shows an association between cannabis and heart function and can’t prove direct causation.Â
There were several limitations, including the study’s small sample size and the lack of comparison between different strains of cannabis.Â