Heart Disease an Issue? Be Careful With Marijuana

Marijuana use is becoming more and more common as states have trended toward legalization of the drug—but that weed, whether used for fun or function, could have unintended consequences for heart health, according to new research.

More than 2 million people with heart disease currently use marijuana or have used it in the past, either recreationally or for approved medical reasons, according to estimates published in a research review in the Journal of the American College of Cardiology. And that’s frightening for researchers, who found there may be an association between using weed and cardiovascular risks.

"We also know that marijuana is becoming increasingly potent,” says lead author Muthiah Vaduganathan, M.D., a cardiologist at Brigham and Women's Hospital's Heart and Vascular Center in Boston, in a news release. “Our review suggests that smoking marijuana carries many of the same cardiovascular health hazards as smoking tobacco. While the level of evidence is modest, there's enough data for us to advise caution in using marijuana for our highest-risk patients, including those who present with a heart attack or new arrhythmia, or who have been hospitalized with heart failure."

The review also cautions that marijuana can interfere with certain medications for cardiovascular problems. For example, if you’re taking lipid-lowering statins and using marijuana your statin levels can climb—that’s because both drugs are metabolized by the same liver enzymes in the body. And if you use marijuana while taking blood thinners, like warfarin, it’s a similar result: The levels of the blood thinners in your blood can increase.

The authors recommend that cardiologists screen their patients to find out whether they use marijuana, how often, and how much—along with the method of delivery. "Vaping marijuana is becoming more and more common, and we know vaping marijuana increases the pharmacological effects of the drug," says Dr. Vaduganathan.

The reviewers recommend people with cardiovascular conditions or with cardiovascular risk factors limit their marijuana use as much as possible. They even go as far as to recommend clinicians screen their heart disease patients—especially younger ones—for marijuana use.

Since these are new recommendations, however, it’s wise to be proactive as the patient rather than waiting for your doc to bring it up. If you have cardiovascular disease and you’re using marijuana, consider having a conversation with your doctor. For those using weed to help with other medical conditions, like the treatment of seizure disorders or to help with nausea and vomiting that can come with chemotherapy, this may mean working with your health care team to find alternative therapies to fill that need.

And while more research on the effects of marijuana on heart health is needed, says Dr. Vaduganathan, that data will likely trickle in slowly, thanks to marijuana still being classified as Schedule I drug in the eyes of the federal government.

"Now that we have seen marijuana use become more popular than tobacco smoking, we need more rigorous research, including randomized clinical trials, to explore the effects of marijuana on cardiovascular health," he says.

But the research we do have is more than enough reason to get to know your personal heart disease risk factors—and talk with your doctor about them (and not just if you’re a weed user!). The main risk factors to know include the following, according to the Centers for Disease Control and Prevention:

• High blood pressure
• Unhealthy blood cholesterol levels
• Diabetes
• Not getting enough physical activity
• Obesity
• An unhealthy diet high in trans-fat, saturated fat, and cholesterol
• Drinking too much alcohol
• Using tobacco
• Genetic factors

Things to Know Before Using Marijuana

If you’re interested in using marijuana to help with health symptoms, it’s important to talk to your doctor first. They can help you understand the available research on potential effects of the drug on your specific condition.

And don’t forget: Your state laws may affect whether marijuana use is even an option. Some states still don’t allow its use at all, while others have only made it legal if used for medically approved reasons. You can get the latest on your specific state’s laws on the National Conference of State Legislature’s website.