Marijuana May Increase Heart Attack and Stroke Risk, Heart Experts Warn

Updated: Nov. 08, 2023

Two breaking studies suggest there's a key question that may be important for doctors to make sure they're asking patients during evaluations.

In 2019, cannabis was the most-used federally illegal drug in the U.S., with greater than 48 million people reportedly having used it in 2019. Now that wider legalization has occurred since then, data suggests usage has increased 20%.

While weed might relieve an ailment or help you chill out—whichever way you consume it—cardiology experts are raising a warning. The American Heart Association (AHA) has expressed mounting concerns based on two new studies that link marijuana use to a higher rate of heart disease and stroke.

How marijuana is consumed can affect individuals differently. As Americans smoke, eat, or vape it, increasingly science is investigating its side effects and long-term health outcomes, such as a potential connection between smoking weed and lung cancer.

Concerning heart disease, the AHA’s two studies—which are expected to be presented at the American Heart Association’s Scientific Sessions 2023 this weekend—both highlight potential risks associated with cannabis use in certain cases. Based on the findings, it seems that heavy users and older individuals at risk for heart disease may face the greatest risks to their heart health with regular cannabis use.

The first study tracked more than 150,000 people who did not have heart failure when they first enrolled in the All of Us Research Program sponsored by the National Institutes of Health. Over the four-year study period, 2% of participants developed heart failure—but alarmingly, those who reported daily marijuana use had a 34% increased risk of developing heart failure.

Further analysis showed that those with existing coronary artery disease were more likely to experience heart health issues due to regular marijuana use. The authors stressed that the study didn’t note how cannabis was consumed during the time period, and thus smoking versus vaping or taking edibles could be a factor to consider for future studies.

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The second AHA study aimed to assess whether older people with type 2 diabetes, high blood pressure, and/or high cholesterol, who reported using marijuana, were at a higher risk for heart issues. The study analyzed data from the 2019 National Inpatient Sample, a large nationwide hospitalization database, focusing on patients with the mentioned risk factors who were 65 years and older.

Among the more than 28,000 people in the sample who met these criteria, 14% more experienced a heart or brain event such as a stroke while they were hospitalized, compared to individuals who didn’t report marijuana use. Marijuana users also experienced a higher rate of heart attacks. High blood pressure and high cholesterol appeared to have played roles for those who had heart or brain-related issues.

What’s evident to the researchers in light of these studies is that healthcare providers should consider cannabis use during examinations and advise patients of risk factors. Dr. Avilash Mondal, the lead author of the second study and a physician at Nazareth Hospital in Philadelphia, PA, says: “Healthcare professionals should ask the question, ‘Are you using cannabis?’ when taking a patient’s history. People often associate ‘smoking’ with cigarette smoking, so it’s important to broaden the conversation to include all forms of cannabis use.”

Dr. Yakubu Bene-Alhasan, the lead author of the first study and a physician at MedStar Health in Baltimore, MD, echoes this sentiment, adding, “Marijuana use isn’t without its health concerns, and our study provides more data linking its use to cardiovascular conditions.” 

Robert L. Page II, chair of the volunteer writing group for the 2020 American Heart Association, agrees: “Together with the results of these two research studies, the cardiovascular risks of cannabis use are becoming clearer and should be carefully considered and monitored by healthcare professionals and the public.”