Daily use of marijuana can increase a person’s risk of coronary heart disease by a third, according to a recent study led by Dr. Ishan Paranjpe, a family physician at Stanford University.
“A growing body of evidence suggests that cannabis is not without harm and may even cause cardiovascular disease,” Paranjpe told CNN. “So the decision to use cannabis must be carefully weighed against the possibility of serious heart disease.”
The study has not yet been published and will be presented Sunday at the annual meeting of the American College of Cardiology.
Researchers used data from the All of Us Research Program to find that daily cannabis users were 34% more likely to be diagnosed with coronary artery disease than those who never used cannabis. Those who took the drug once a month or less were not found to be at significant risk.
Coronary artery disease (CAD) is the most common form of heart disease in the U.S. and sometimes goes undetected until the affected person has a heart attack, according to the Centers for Disease Control and Prevention. Being overweight, physical inactivity, an unhealthy diet, and smoking tobacco are all risk factors for CAD, which are often associated with symptoms of chest pain, nausea, light-headedness, shortness of breath, and pain in the arms or shoulders.
The study used an often untapped method in marijuana and heart health, Mendelian randomization (MR) – which measures gene variations related to modifiable risk factors.
“While other work has also linked cannabis to CAD, there are several potential confounders that may explain this relationship,” Paranjpe said. “Our MR analysis suggests that this relationship may be directly causal.”
The researchers argued that future research should examine how different methods of marijuana use affect heart health, since the study failed to prove whether different types of use change a user’s risk of developing CAD.