Marijuana, or cannabis, has come a long way since you had to sneak off and smoke a joint. Today, it’s legal in states like New Jersey for medicinal and recreational use, and the ingredient compound found in the cannabis plant called cannabidiol (CBD) is commonly found in creams, oils, and even brownies.

But, if you have heart disease or are at high risk for it, you might be wondering if cannabis is safe to use. The American Heart Association (AHA) raised a red flag about it this summer in its journal Circulation.

Because cannabis is still illegal at the federal level, reliable clinical studies are scarce. Many are short-term, observational, or retrospective. What we have learned is its safety and possible use as a treatment can depend on its form.

Outlining the uncertainties of cannabis use        

According to the AHA statement’s authors, cannabis may:

• Increase your risk for heart attack, stroke, heart failure, chest pain, and the heart rhythm disorder atrial fibrillation (although additional research is needed to verify observational studies)
• Interact with medications such as blood thinners, antidepressants, antipsychotics, antiarrhythmics for heart rhythm abnormalities, and statins for reducing cholesterol levels
• Increase your need to be hospitalized, especially if you're older, pregnant, or have a preexisting heart condition

It appears many of the adverse effects are related to tetrahydrocannabinol (THC), an active chemical in the cannabis plant that makes you feel high. THC stimulates the sympathetic nervous system, which directs the body’s “fight or flight” response to dangerous or stressful situations. Using cannabis products that contain THC can cause a higher heart rate and blood pressure, a greater demand for oxygen, and artery dysfunction.

In contrast, CBD has been found to lower blood pressure and heart rate, reduce inflammation, and increase the ability of arteries to open.

Avoid smoking marijuana for your overall health

In addition to form, the way you consume cannabis may influence how it affects your heart and blood vessels.

Inhaling cannabis, regardless of its THC content, greatly increases your intake of carbon monoxide and tar, just like a tobacco cigarette. You should never smoke or vape any substance.

Talk to your doctor about what's right for you

While cannabis has shown potential for treating Parkinson’s, Alzheimer’s, and multiple sclerosis, we don’t have studies yet that show its potential for treating heart disease.

If you’re using or considering using cannabis, talk with your physician about how it may affect your health.