Marijuana is known for its effects on the nervous system, particularly its ability to create a sense of euphoria and relaxation. Some doctors may even prescribe medical marijuana to patients with cancer, AIDS or HIV to help ease pain and stimulate appetite. But how does marijuana affect other parts of the body, such as the heart? While some studies have found little connection between marijuana use and cardiovascular disease, others have found links.
“Studies to better understand how marijuana affects the cardiovascular system are ongoing,” says Dr. Bryant Nguyen, a cardiologist affiliated with Sharp Grossmont Hospital. “As we see marijuana being legalized by more states across the country for both medicinal and recreational use, it makes it all the more important for clinicians and researchers to learn about how certain components found in marijuana affect the body.”
For instance, researchers have linked marijuana use to an increase in blood pressure, heart rate and chest pains during exercise. Recent studies have also found a connection between marijuana and heart-related conditions such as coronary artery disease and heart failure. Here is an overview of what else is known about marijuana use and cardiovascular conditions.
Certain chemicals in marijuana can directly impact the heart and blood vessels, which may increase the risk of heart attacks. According to researchers, daily marijuana use may increase heart attack risk by 1.5 to 3 percent. Marijuana may trigger these heart attacks by causing the coronary arteries to constrict, a condition known as coronary arterial vasospasm.
Scientists in France recently published findings after reviewing more than 800 medical studies and reports on marijuana. Of these reports, approximately 115 contained data on patients who used marijuana and experienced cardiovascular events. Most of the patients — who were male and in their early 30s — mainly experienced heart attack or stroke. Some of the data specifically showed a stronger association between marijuana use and ischemic stroke, which is caused by a blood clot that blocks blood flow to the brain.
Additionally, a 2016 study also demonstrated an association between stroke and marijuana use. Using data from the Nationwide Inpatient Sample, the largest inpatient database in the U.S., researchers focused on users and nonusers who were hospitalized for an acute ischemic stroke from 2004 to 2011. They found that among younger adults in their 20s and 30s — where marijuana use was more prevalent — recreational marijuana use was associated with a 17 percent increased likelihood of being hospitalized for acute ischemic stroke.
Data from the Nationwide Inpatient Sample was also analyzed in a separate study where scientists found a link between marijuana and stress cardiomyopathy, also known as “broken heart syndrome” — the weakening of the heart muscle triggered by physical or emotional stress. Those who used marijuana were almost twice as likely to develop stress cardiomyopathy compared to nonusers. Again, marijuana users identified in the database were usually younger, male and had fewer risk factors for cardiovascular disease.
However, despite fewer cardiovascular risks and being younger, they were more prone, compared to nonusers, to go into cardiac arrest during stress cardiomyopathy. Based on these findings, the researchers suggest that those who use marijuana and develop chest pain or shortness of breath should see their doctor to rule out any heart problems.
“The medical community’s knowledge of the pros and cons of marijuana is limited, and there is still much to learn,” says Dr. Nguyen. “Whether you choose to consume marijuana for medical or recreational purposes, it’s important to be aware of any potential risks, pay careful attention to your body and discuss any unusual symptoms with a doctor.”
For the news media: To talk with Dr. Nguyen about the effects of marijuana on the heart, contact Erica Carlson, senior public relations specialist, at firstname.lastname@example.org.