The legalization of recreational cannabis may be contributing to a rise in heart attacks and some other cardiovascular problems, according to a
study published in
BMJ Open.
Why It’s Relevant
Many chemicals found in cannabis—notably tetrahydrocannabinol (THC)—can raise blood pressure, increase heart rate, and induce platelets to clump. These changes can pose cardiovascular risks, especially in older adults—a population that is finding cannabis products
more attractive.
For this analysis, researchers made use of a national U.S. database to examine more than 50 million hospital admissions from 2012-2018. This period provided a natural experiment: By January 2018, nearly 80% of people in the Western U.S. (Alaska, Arizona, California, Colorado, Hawaii, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming) were living in a state with recreational cannabis sales, whereas the first Eastern state to provide recreational cannabis permits was Massachusetts in November 2018.
By the Numbers
- In 2012 and 2013, overall admission rates for six cardiovascular outcomes were similar among people in the Eastern and Western U.S. regions.
- Starting in 2014 (when Colorado and Washington enacted recreational cannabis sales), hospital admissions for atrial fibrillation, heart attack, and heart failure were 2% to 4% higher for each year of legalization in the Western region.
- However, there was no difference in rates of ischemic stroke, ventricular tachycardia, or venous thromboembolisms.
- As the researchers anticipated, admissions for cannabis-related diagnoses also rose faster in the Western U.S. beginning in 2014 (13.6% increase each year).
The Other Side
This analysis did not break down data from individual states, and the regional comparison oversimplified the spread of recreational cannabis in the West. Further, though the researchers adjusted for many sociodemographic differences between the two regions, there may have been variables that differentially impacted cardiovascular health in Western versus Eastern state populations from 2014-2018 that were missed.
Takeaway Message
“Globally, our findings support a cautious approach to legalization laws accompanied by data collection on [cardiovascular] outcomes,” the researchers wrote. They added that their results support recent U.S. efforts to
federally reclassify cannabis from Schedule I to the less-restrictive Schedule III, which would allow for more cannabis-related research.
Related Information
Source
Samuel D. Slavin, et al. Cannabis legalisation and cardiovascular hospitalisations in the United States: nationwide difference-in-differences analysis, 2012–2018.
BMJ Open. Published October 22, 2026. doi:
10.1136/bmjopen-2025-111050
(Image: Getty Images/iStock/megaflopp)