How You Use Cannabis Changes What It Does to Your Heart and Lungs: A Systematic Review by Route | Research

The takeaway

Smoking cannabis carries the most cardiovascular and respiratory risks, vaping may reduce respiratory harm but has its own concerns, and edibles/dabbing are poorly studied — the route of administration matters enormously.

Read this if you use cannabis and want to make an informed choice about how — the route you choose significantly changes the health risks.

What the researchers found

Most cannabis health research lumps all users together regardless of whether they smoke flower, vape concentrates, eat edibles, or dab. This systematic review specifically examined how the route of administration changes cardiovascular and respiratory outcomes — a critical distinction as the market diversifies.

Among 42 studies meeting inclusion criteria, four administration routes emerged: smoking, vaping, oral ingestion, and dabbing. The findings varied dramatically by route.

Smoking was the most studied and carried the clearest risks: increased heart rate, elevated blood pressure, higher risk of myocardial infarction (especially in the hour after smoking), and respiratory effects including chronic bronchitis symptoms, airway inflammation, and impaired mucociliary clearance. These cardiovascular effects are acute and largely driven by the combustion products, not just the cannabinoids.

Vaping showed a potential for harm reduction on the respiratory side — reduced combustion byproducts and fewer bronchitic symptoms — but raised concerns about EVALI (e-cigarette/vaping-associated lung injury) and unknown long-term effects from inhaling vaporized concentrates and additives.

Oral ingestion was the least studied for cardiopulmonary effects. The slower onset and longer duration of edibles creates a different pharmacokinetic profile that might produce less acute cardiovascular stress, but data is sparse.

Dabbing — flash-vaporizing cannabis concentrates at high temperatures — was barely studied at all, despite delivering extremely high THC doses that could have significant cardiovascular effects.

Why it matters

As cannabis products diversify — from flower to vapes to edibles to concentrates — health advice needs to be route-specific. Telling someone 'cannabis increases heart attack risk' is incomplete if the risk is primarily from smoking. This review provides the framework for route-specific risk counseling, which is what both clinicians and consumers actually need.

The numbers in context

42 studies included from 1,873 retrieved. Four routes identified: smoking (most studied), vaping, oral ingestion, dabbing (least studied). Smoking associated with acute heart rate increase, blood pressure elevation, MI risk, chronic bronchitis, and airway inflammation. Vaping showed reduced respiratory harm but EVALI concerns. Oral and dabbing data sparse.

How the study worked

Systematic review following PRISMA guidelines. Searched Web of Science, ProQuest, PsychINFO, Scopus, Embase, and Medline databases. Included peer-reviewed articles (2009-2023) reporting cardiovascular or respiratory effects of cannabis by route of administration. Excluded studies without route information or those combining cannabis with other illicit substances. 42 studies included: 6 case reports, 21 reviews, 15 empirical studies.

Who was studied

42 studies (N=varied participants) focusing on cardiovascular and respiratory effects of cannabis use.

What this study cannot tell us

Only 42 studies met criteria, and many were case reports or reviews rather than original empirical research. Dabbing and oral ingestion are severely understudied relative to their market prevalence. Many studies didn't distinguish between cannabis-only users and those who also smoke tobacco. The 2009-2023 timeframe captures the legalization era but may miss early foundational research. Product composition (THC concentration, additives, carrier oils) varied enormously and was often unreported.

How to read the evidence

Systematic review following PRISMA guidelines, but limited by the poor quality and small number of studies for non-smoking routes. The evidence is strongest for smoking risks and weakest for edibles and dabbing.

When this study was published

Published in 2024. As the cannabis market diversifies, route-specific research is increasingly urgent.

The bigger picture

This complements RTHC-00110 (marijuana and lung health review) by adding the cardiovascular dimension and differentiating by route. It also extends RTHC-00103 (cardiovascular meta-analysis) by addressing whether the stroke association found in that meta-analysis might be route-specific. The vaping harm reduction angle connects to the public health debate about encouraging safer consumption methods in legal markets.

Replication

Not stated in abstract.

Funding

Not reported in abstract.

Conflicts of interest

Not reported in abstract.

Questions still open

Would switching from smoking to edibles significantly reduce cardiovascular risk? Are the cardiovascular effects of dabbing (extremely high acute THC doses) worse than smoking? Should public health agencies actively recommend route-switching as harm reduction? Is the MI risk from smoked cannabis driven by combustion products (like tobacco) or by THC's acute cardiovascular effects?

Read the original research

Cardiovascular and Respiratory Effects of Cannabis Use by Route of Administration: A Systematic Review.

Substance use & misuse, 59(9), 1331-1351

Substance Use & Misuse is a peer-reviewed journal focusing on substance use and its effects.

View on PubMed ↗Publisher’s paper ↗

Citation

Muheriwa-Matemba, Sadandaula Rose; Baral, Amrit; Abdshah, Alireza; Diggs, Bria-Necole Amazing; Gerber Collazos, Kathryn Sierra; Morris, Kyana Breche; Messiah, Sarah Elizabeth; Vidot, Denise Christina. (2024). Cardiovascular and Respiratory Effects of Cannabis Use by Route of Administration: A Systematic Review.. Substance use & misuse, 59(9), 1331-1351. https://doi.org/10.1080/10826084.2024.2341317