Daily Marijuana Use Linked to Heart Disease

A major new study finds that people who used marijuana daily were about one-third more likely to develop coronary artery disease compared with people who have never used the drug.

“We found that cannabis use is linked to [heart disease], and there seems to be a dose-response relationship in that more frequent cannabis use is associated with a higher risk,” said Ishan Paranjpe, MD, a resident physician at Stanford University and the study’s lead author.

“In terms of the public health message, it shows that there are probably certain harms of cannabis use that weren’t recognized before, and people should take that into account,” Paranipe said.

The study was presented at the American College of Cardiology’s Annual Scientific Session Together With the World Congress of Cardiology. It's among the largest and most comprehensive to date to examine the potential long-term cardiovascular implications of using the drug.

Coronary artery disease is the most common form of heart disease and occurs when the arteries that supply blood to the heart become narrowed due to a buildup of cholesterol. It commonly causes chest pain, shortness of breath and fatigue, and can lead to a heart attack.

Previous results were mixed

Previous studies have reported somewhat mixed findings on the relationship between cannabis and heart disease, with some suggesting that smoking marijuana can raise the risk of heart attack, stroke and other cardiac events, especially in younger people.

Using data from the All of Us Research Program of the National Institutes of Health, which includes detailed information about the health and habits of 175,000 people, researchers first analyzed the relationship between cannabis use frequency and rates of heart disease.

After adjusting for age, sex and major cardiovascular risk factors, the results indicated that daily cannabis users were 34% more likely to have heart disease those who have never used marijuana. In contrast, monthly cannabis use was not associated with a significant increase in risk.

Based on these findings, researchers said it is important for people to be aware that cannabis use is not without risk and make sure to inform their doctor if they use cannabis so that clinicians can take appropriate steps to monitor their heart health.

“From a scientific standpoint, these findings are exciting because they suggest there might be new drug targets and mechanisms we can explore to take control of this pathway going forward,” Paranjpe said.

Although the use and possession of cannabis remains illegal under federal law, over half of U.S. states have legalized or decriminalized recreational use of marijuana and three-quarters allow it to be used for medical purposes. A study conducted in 2019 estimated that about 18% of U.S. adults used marijuana in that year.