Cannabis Linked Strongly to Heart Issues

A cannabis plant at the Cannabis Expo Brazil, a hemp and cannabis industry exhibition, in Sao Paulo, Brazil, on Sept. 15, 2023. (Nelson Almeida/AFP via Getty Images)

Using marijuana in any way considerably raises the risk of heart issues, according to a new study published in the Journal of the American Heart Association (JAHA).

Daily users have a 25 percent higher chance of a heart attack, and a 42 percent higher risk of stroke, the researchers found.

The peer-reviewed study, published on Feb. 28, looked at data from 434,104 individuals from 27 U.S. states and two territories who were surveyed between 2016 and 2020. Four percent of respondents used cannabis daily while 7.1 percent used it on a non-daily basis.

The study found that any type of cannabis use—smoking, eating, or vaporizing—has “strong, statistically significant associations with adverse cardiovascular outcomes” like coronary heart disease, myocardial infarction, and stroke.

Heavier use—using cannabis more days per month—was associated with “higher” odds of adverse outcomes.

The results were similar even after controlling for other cardiovascular risk factors like tobacco use, body mass index, type 2 diabetes, alcohol consumption, and physical activity.

“Patients should be screened for cannabis use and advised to avoid smoking cannabis to reduce their risk of premature cardiovascular disease and cardiac events,” the researchers recommended.

The study also looked at adults at risk for premature cardiovascular disease, which includes men below 55 years of age and women younger than 65 years.

Among these groups, cannabis use was linked to a 36 percent higher risk for coronary heart disease, heart attack, and stroke. Individuals who did not smoke tobacco cigarettes or nicotine e-cigarettes also had higher cardiovascular risks when they smoked cannabis.

“Despite common use, little is known about the risks of cannabis use and, in particular, the cardiovascular disease risks,” said lead study author Abra Jeffers, a data analyst at Massachusetts General Hospital in Boston.

“The perceptions of the harmfulness of smoking cannabis are decreasing, and people have not considered cannabis use dangerous to their health. However, previous research suggested that cannabis could be associated with cardiovascular disease,” she said.

“In addition, smoking cannabis—the predominant method of use—may pose additional risks because particulate matter is inhaled.”

Robert L. Page II, a professor of clinical pharmacy, pointed out that the findings of the study have important implications for public health and says it should be a call to action for all medical personnel.

“As cannabis use continues to grow in legality and access across the U.S., practitioners and clinicians need to remember to assess cannabis use at each patient encounter in order to have a non-judgmental, shared decision conversation about potential cardiovascular risks and ways to reduce those risks.”

The study received funding from the National Cancer Institute and the National Heart, Lung, and Blood Institute, which are both part of the National Institutes of Health.

The authors said these institutions had no role in the conduct of the study. One of the authors revealed a potential conflict of interest, having served as a consultant to the World Health Organization (WHO).

Heart Issues

Multiple other studies also have associated marijuana or cannabis with cardiovascular risks. Danish researchers in 2022 found that even the use of medical cannabis was associated with a 64 percent higher risk of arrhythmia, which is an irregular heartbeat.

The U.S. Centers for Disease Control and Prevention (CDC) also states that marijuana can cause the heart to beat faster and make blood pressure spike in the near term. In addition, it “could also lead to increased risk of stroke, heart disease, and other vascular diseases.”

“Marijuana smoke also delivers many of the same substances researchers have found in tobacco smoke—these substances are harmful to the lungs and cardiovascular system,” it stated.

“It is hard to separate the effects of marijuana chemicals on the cardiovascular system from those caused by the irritants and other chemicals that are present in the smoke.”

While cannabis is illegal at the federal level, 24 states and Washington D.C. have legalized its recreational use.

A recent Gallup poll showed that 17 percent of Americans smoked marijuana last year, up from 11 to 13 percent from 2015 to 2021.  In 2013, only 7 percent of Americans said they used it.

“Age is a significant driver of the likelihood of smoking marijuana. About a quarter of young adults, those aged 18 to 34, say they smoke marijuana (26 percent), but reported use falls to 18 percent among adults aged 35 to 54 and is even lower, 11 percent, among adults aged 55 and older,” Gallup stated.

Men were found to be more likely than women to use marijuana. While 21 percent of individuals without a college degree admitted to smoking marijuana, the number dropped to 9 percent among college graduates.

In terms of politics, Democrats had the highest proportion of marijuana users, with 22 percent.

Independents followed at 17 percent and Republicans at 12 percent.