Smoking cannabis linked to increased risk of heart attack, stroke

Smoking cannabis is associated with an increased risk of a heart attack or stroke, according to a new study. 

The study, published Wednesday in the Journal of the American Heart Association, found daily use of cannabis — predominantly through smoking — was linked with a 25 percent increased likelihood of heart attack and a 42 percent increased likelihood of a stroke when compared to nonusers of cannabis. 

Less frequent use of cannabis also was linked to an increased risk of cardiovascular events, with weekly users showing a 3 percent increased chance of a heart attack and a 5 percent increased chance of a stroke. 

The study, funded in part by the National Institutes of Health, used data from nearly 435,000 American adults from 2016 to 2020. About 75 percent of the study’s respondents said they primarily used cannabis by smoking it, while 25 percent said they used the drug through other methods, including vaping, drinking or eating it. 

“We know that toxins are released when cannabis is burned, similar to those found in tobacco smoke," wrote lead study author Abra Jeffers, Ph.D., a data analyst at Massachusetts General Hospital in Boston, in a release with the NIH. 

Researchers added the link between cannabis and cardiovascular diseases was also observed among those who have never used tobacco cigarettes or electronic cigarettes. 

Jeffers noted scientists have known for a long time that tobacco smoking is linked to heart disease, and that same trend is now being seen with cannabis. 

“Cannabis use could be an important, underappreciated source of heart disease,” she said. 

Researchers said the specific mechanisms linking cannabis with heart disease are not clear but pointed to various potential factors including endocannabinoid receptors, which recognize THC, the main psychoactive ingredient in cannabis. 

Citing their findings, researchers called on patients and policymakers to become informed about the associated risks of cannabis use, especially in the wake of the “declining perception of risk” currently associated with cannabis as it becomes legal in many states.

The study used data from the Behavioral Risk Factor Surveillance System, an annual phone survey conducted by the US Centers for Disease Control and Prevention (CDC) across the nation.