Cannabis Smoking Is an Independent Risk Factor for Heart Attack, but Edibles May Not Be | Research

The takeaway

A systematic review of 22 studies found cannabis smoking independently increased heart attack risk (aORs: 1.03-5.24) even after adjusting for tobacco, while non-smoked cannabis (edibles, vaping) was not significantly associated with heart attack risk.

Cardiologists, cannabis users with heart disease risk, and harm reduction advocates

Non-smoked cannabis showed no significant heart attack risk (aOR=1.00)

What the researchers found

After adjusting for tobacco use, cannabis smoking remained significantly associated with heart attack, with adjusted odds ratios from 1.03 to 5.24, particularly high in younger age groups. Among never-tobacco smokers, frequent cannabis smoking still increased MI risk (aOR=1.88). Non-smoked cannabis (primarily ingestion) was not associated with significant MI risk (aOR=1.00 for frequent use, aOR=1.31 ns for current use).

Why it matters

This is the first systematic review to distinguish between cannabis smoking and non-smoked cannabis for heart attack risk. The finding that the route of administration matters has major implications: the cardiac risk may be from combustion-related toxins (like carbon monoxide) rather than cannabinoids themselves.

The numbers in context

22 studies reviewed. Cannabis smoking aORs: 1.03-5.24. In never-tobacco smokers: aOR=1.88 for frequent cannabis smoking. Non-smoked cannabis frequent use: aOR=1.00 (not significant). Non-smoked current use: aOR=1.31 (not significant).

How the study worked

Systematic review following PRISMA guidelines, searching PubMed, Embase, and Google Scholar. 22 eligible studies identified examining cannabis use variations and myocardial infarction risk.

What this study cannot tell us

Relatively few studies examined non-smoked cannabis specifically, limiting those conclusions. Most non-smoked use was edibles; vaping data was sparse. Residual confounding from polysubstance use, lifestyle factors, and socioeconomic status cannot be fully excluded.

How to read the evidence

Systematic review of 22 studies with consistent findings for smoked cannabis, though limited data on non-smoked routes.

When this study was published

2024 systematic review

The bigger picture

The distinction between smoked and non-smoked cannabis for cardiac risk parallels the tobacco experience. If combustion is the key driver, harm reduction approaches (switching to edibles, vaping) could substantially reduce cannabis-related heart attack risk.

Questions still open

Does cannabis vaping carry the same or less cardiac risk than smoking? Is the carbon monoxide exposure from cannabis combustion the primary mechanism? Should cardiac patients be counseled to switch from smoked to non-smoked cannabis?

Common questions

Does cannabis cause heart attacks?

Smoking cannabis appears to independently increase heart attack risk, with odds ratios up to 5.24 even after adjusting for tobacco use. However, non-smoked cannabis (edibles, primarily) was not associated with significant heart attack risk.

Is there a safer way to use cannabis for heart health?

This review suggests that the cardiac risk is primarily from smoking (combustion) rather than cannabinoids themselves. Non-smoked forms like edibles showed no significant heart attack risk, though more research is needed.

Read the original research

Cannabis Use Variations and Myocardial Infarction: A Systematic Review.

Journal of clinical medicine, 13(18)

View on PubMed ↗Publisher’s paper ↗

Citation

van Amsterdam, Jan; van den Brink, Wim. (2024). Cannabis Use Variations and Myocardial Infarction: A Systematic Review.. Journal of clinical medicine, 13(18). https://doi.org/10.3390/jcm13185620