Is Smoking Weed as Bad for Your Heart as Cigarettes?

In a new report researchers at Brigham and Women's Hospital estimate nearly two million U.S. adults who have heart disease report using marijuana.


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Here’s something to be blunt about: A new study has found that using pot carries many of the same hazards for heart health as smoking tobacco.

In a report released today in The Journal of the American College of Cardiologya team of researchers at Brigham and Women’s Hospital found that nearly two million U.S. adults with heart disease reported using marijuana at some point in their life. The data for the study was gathered from responses to the Centers for Disease Control and Prevention’s National Health and Nutrition Examination Survey between 2005-2016. Participants in the survey were asked if they ever used marijuana or hashish, a drug made from the resin of the cannabis plant, and if they had ever been diagnosed with heart disease including heart failure, congestive heart failure, coronary heart disease, or heart attack.

The report underscores how we’re entering new territory in understanding the health impacts of marijuana use. “For the first time more people are using marijuana as opposed to smoking cigarettes,” says Dr. Muthiah Vaduganatham, a cardiologist at the Brigham and one of the researchers behind the report. “Because of this we, as a community, need to focus our attention to identifying strategies to promote its safe use.” But because marijuana is classified as a schedule I drug by the U.S. Drug Enforcement Agency, its research is highly restricted and it is illegal to conduct rigorous controlled trials of marijuana products in the United States.

The researchers found that many of the same toxic chemicals released by cigarettes are also found in marijuana smoke. Inhaling cannabis may increase heart rate and blood pressure causing a heart attack, and those using marijuana are more likely to experience abnormal heart rhythms and stroke. While it’s pretty obvious that inhaling anything into the lungs besides good ‘ole oxygen is less than ideal, Vaduganatham points out marijuana use—in any of its forms—affects the heart by issuing changes to things like sympathetic tone and blood pressure. He also points out how marijuana can disrupt the efficacy of cardiovascular medications.

The findings, however, don’t mean we should stop using medical marijuana. Since cannabis is used for a wide range of medical treatments—from managing conditions such as epilepsy to easing pain during cancer treatments—Vaduganatham says health care decisions should be made on a case-by-case basis that weigh the risks of any drug against its benefits.

More than anything else, the report is a call for more research. Although clinical trials of marijuana are illegal, Vaduganatham says that more studies involving a large amount of data, like this one, are possible and encouraged. The researchers also urge clinicians to ask their patients about marijuana use and to keep the dialogue open. Either way you light it, maybe you should think twice next time before you puff, puff, pass—or maybe you already have—and in that case, this is just a friendly reminder.