Marijuana Use Not Associated with Increased Risk of Atherosclerosis

Bern, Switzerland: The cumulative use of cannabis over a 20-year period is not independently associated with an increased risk of atherosclerosis (hardening of the arteries), according to longitudinal data published in The American Journal of Medicine.

An international team of investigators from Switzerland and the United States assessed the relationship between the use of tobacco and/or cannabis and the risk of subclinical atherosclerosis in a cohort of 3,257 subjects. 

Authors reported that lifetime exposure to tobacco over a 20-year period was “strongly associated” with subclinical atherosclerosis, whereas the cumulative use of cannabis alone was not – a finding that is consistent with prior research

They concluded, “This study adds to the growing body of evidence that there might be no association between the average population level of marijuana use and subclinical atherosclerosis.”

Previous research published by several of the same investigators reports that the cumulative use of cannabis is not associated with an increased risk of either cardiovascular disease or coronary heart disease in middle-age subjects.

Other analyses of nationally representative samples of recreational marijuana consumers have reported inconsistent results regarding the relationship between cannabis and adverse cardiovascular events. A 2021 study of 57,000 US adults concluded, “After controlling for several confounding variables, we found that there was a decrease in the prevalence of cardiovascular events with marijuana use (Odds Ratio: 0.74).” By contrast, a 2020 review of nearly 134,000 US adults reported, “Frequent marijuana smoking is associated with significantly higher odds of stroke and myocardial infarction or coronary artery disease, with a possible role in premature cardiovascular disease.” More recently, the results of a 2021 literature review of 67 studies published in The American Journal of Medicine concluded, “[M]arijuana itself does not appear to be independently associated with excessive cardiovascular risk factors.” Authors did caution, however, that “it can be associated with other unhealthy behaviors such as alcohol use and tobacco smoking that can be detrimental” to cardiovascular health.

Full text of the study, “Cumulative marijuana use and carotid intima-media thickness at middle age: the CARDIA study,” appears in The American Journal of Medicine.