Analysis: Marijuana Use Not Associated with Elevated Risk of Heart Attack 

San Diego, CA: A history of cannabis use within the past year is not associated with an increased risk of heart attack among middle-aged adults, according to data published in the American Journal of Cardiology.

Investigators affiliated with the University of California, San Diego assessed the relationship between cannabis use and physician-diagnosed myocardial infarction (MI) in a nationally representative group of nearly 10,000 middle-aged (35 to 59 years old) subjects. 

Compared to non-users, current consumers of cannabis (those who had used marijuana monthly for the past year) did not possess a higher risk of heart attack after researchers adjusted potential confounders (e.g., physical activity, BMI, alcohol and cigarette use). Those who reported consistent monthly cannabis use for the past decade also possessed no greater risk.

By contrast, researchers did identify an increased risk among a portion of former consumers who had recently ceased using cannabis. Investigators called this latter finding “unexpected.”

Authors concluded: “In a representative sample of middle-aged US adults, a history of monthly cannabis use for more than a year before a myocardial infarction was not linked to a subsequent physician-diagnosed MI, after accounting for cardiovascular risk factors. However, when considering recent use, the odds were three times greater if no use was reported in the past month. The length of monthly use before the MI, including use >10 years, also showed no association. The evidence base for cardiovascular harms is conflicting and limited by the ability to accurately quantify use, especially the method of use, dose, and potency. Given the expanding access to cannabis products in the United States and around the world, more research, particularly longitudinal and experimental studies, is needed.”

Cannabinoids have long been known to influence cardiovascular function, though data regarding the degree of these effects are inconsistent. According to the results of a 2021 literature review of 67 studies published in the American Journal of Medicine, “[M]arijuana itself does not appear to be independently associated with excessive cardiovascular risk factors,” although authors did caution 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, “Associations between monthly cannabis use and myocardial infarction in middle-aged adults: NHANES 2009 to 2018,” appears in the American Journal of Cardiology.