News release
Wednesday, February 28, 2024
An observational study funded by the NIH showed that the risk increased sharply with more frequent use.
Frequent smoking of cannabis may significantly increase the risk of heart attack and stroke, according to an observational study supported by the National Institutes of Health. The study, published in Journal of the American Heart Associationused data from nearly 435,000 American adults and is among the largest ever to examine the relationship between cannabis and cardiovascular events.
The study, funded by the National Heart, Lung, and Blood Institute (NHLBI), part of the NIH, found that daily cannabis use — mostly through smoking — was associated with a 25 percent increased likelihood of heart attack and a 42 percent increased likelihood of stroke in compared to not using the drug. Less frequent use is also associated with an increased risk of cardiovascular events. Weekly users show a 3% increased chance of heart attack and a 5% increased chance of stroke.
About 75% of survey respondents reported that they primarily used cannabis by smoking the drug. Approximately 25% of respondents reported using cannabis in some way other than smoking, such as vaping, drinking, or eating the drug.
“We know that burning cannabis releases toxins similar to those found in tobacco smoke,” said corresponding author Abra Jeffers, Ph.D., a data analyst at Massachusetts General Hospital in Boston and a former researcher at the Center for Tobacco . Control Research and Education at the University of California, San Francisco, where she conducted the study as part of her postdoctoral work.
“We have long known that smoking tobacco is associated with heart disease, and this study is evidence that smoking cannabis also appears to be a risk factor for cardiovascular disease, which is the leading cause of death in the United States,” Jeffers said. “Cannabis use may be an important, underappreciated source of heart disease.”
The researchers note that while the exact mechanisms linking cannabis to heart disease are unclear and were not examined in the current study, multiple factors may play a role. In addition to toxins, endocannabinoid receptors — the part of cells responsible for recognizing tetrahydrocannabinol (THC), the main psychoactive ingredient in cannabis — are widespread in the body’s cardiovascular tissues and may facilitate cardiac risks.
Cannabis use has increased significantly over the past 20 years across the country as negative perceptions of its use have declined, according to government surveys on drug use and health. In the United States, cannabis is now legal in 38 states for medical use and in 24 states for recreational use. Some studies have linked its regular use to impaired brain development and lung damage, as well as some cardiovascular diseases. However, there are gaps in knowledge about the adverse effects of cannabis on the heart.
To take a closer look at the links between cannabis use and health, Jeffers and her research team used 2016-2020 data from the Centers for Disease Control and Prevention’s Behavioral Risk Factor Surveillance Study. The national cross-sectional survey, conducted annually by the CDC, includes 434,104 adults aged 18-74 from 27 US states and two territories. Most of the respondents were white (60%), while about 12% were black, 19% were Hispanic, and 9% were of another race/ethnicity.
Researchers assessed the relationship between cannabis smoking (the number of days participants said they smoked the drug in the past 30 days) and cardiovascular outcomes, including coronary heart disease, heart attack, stroke, and a combined measure of all three. They adjusted for the participants’ tobacco use and other characteristics, including their age, gender, race, body mass index or BMI, obesity, diabetes, physical activity levels and socioeconomic status.
“This is an important public health finding, especially given our ongoing efforts to reduce the burden of heart disease in this country,” said David S. Goff, MD, Ph.D., director of the Division of Cardiovascular Sciences at NHLBI.
“Questioning patients about their cannabis use during routine medical exams or medical exams in much the same way they might be asked about tobacco use will help us learn more about the long-term effects of marijuana on the body,” Jeffers said.
study was funded in large part by NHLBI under grant 1R01HL130484-01A1 and included additional support from National Cancer Institute grant T32 CA113710. For fuller funding disclosure and list of authors, please see the full JAHA research paper.
About the National Heart, Lung, and Blood Institute (NHLBI): The NHLBI is a global leader in conducting and supporting research in heart, lung and blood diseases and sleep disorders that advances scientific knowledge, improves public health and saves lives. For more information visit https://www.nhlbi.nih.gov.
For the National Institutes of Health (NIH):NIH, the national agency for medical research, includes 27 institutes and centers and is part of the US Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research and investigates the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.
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