Could the Body's Cannabis System Protect the Heart? | Research

The takeaway

A comprehensive review found evidence that endocannabinoids play important protective roles during cardiovascular emergencies including shock and heart attacks, acting through CB1 receptors, vanilloid receptors, and possibly novel receptors.

Read this if you want to understand how the body's own cannabis system interacts with heart health.

Endocannabinoids show protective roles in shock and myocardial infarction

What the researchers found

The review documented multiple mechanisms by which cannabinoids affect the cardiovascular system. CB1 receptors are present in the heart and blood vessels, and endocannabinoids act through them to regulate cardiovascular function. Anandamide also activates vanilloid VR1 receptors on sensory nerves, releasing the vasodilatory peptide CGRP.

Importantly, evidence suggested endocannabinoids had protective roles in pathological conditions such as shock and myocardial infarction. Some cardiovascular effects appeared to involve receptors beyond the currently identified CB1 and CB2, and the cannabinoid receptor family appeared related to a broader family of lipid receptors linked to similar signaling pathways.

Why it matters

While much attention focused on the risks of cannabis for cardiovascular health, this review highlighted the other side: the endocannabinoid system appeared to play protective roles during cardiovascular emergencies. This suggested that understanding and modulating this system could lead to new treatments for heart disease and shock.

The numbers in context

No specific quantitative data were highlighted in the abstract.

How the study worked

This was a comprehensive review published in Biological Reviews covering cannabinoid receptor pharmacology, endocannabinoid signaling, and cardiovascular effects including potential protective mechanisms in pathological conditions.

What this study cannot tell us

Much of the evidence was from animal models and isolated tissue preparations. The clinical significance of endocannabinoid cardioprotection in humans remained unclear. The complexity of multiple receptor types and signaling pathways made simple therapeutic applications difficult.

How to read the evidence

This is a comprehensive review in a biology journal synthesizing pharmacological and physiological evidence, providing moderate-level evidence.

When this study was published

Published in 2004. Endocannabinoid cardioprotection remains an active research area.

The bigger picture

The concept of endocannabinoid cardioprotection has been further explored, with research into how the endocannabinoid system responds to ischemia and reperfusion injury. While no endocannabinoid-based cardiovascular treatments have been developed, the protective mechanisms described here remain an active research area.

Questions still open

Could drugs enhancing endocannabinoid signaling protect the heart during a heart attack? Do the cardiovascular protective effects of endocannabinoids explain why acute cannabis cardiovascular events are relatively rare?

Common questions

Is cannabis good or bad for the heart?

The relationship is complex. While cannabis use can increase heart rate and occasionally trigger cardiovascular events, this review showed that the body's own endocannabinoid system actually plays protective roles during heart emergencies. External cannabis and internal endocannabinoids may affect the heart through different mechanisms.

What is a vanilloid receptor?

The VR1 (now called TRPV1) receptor responds to capsaicin (the compound in chili peppers) and also to the endocannabinoid anandamide. In blood vessels, its activation releases peptides that cause dilation, potentially contributing to cannabis's blood pressure effects.

Read the original research

Cannabinoid pharmacology in the cardiovascular system: potential protective mechanisms through lipid signalling.

Biological reviews of the Cambridge Philosophical Society, 79(1), 187-205

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Citation

Hiley, C Robin; Ford, William R. (2004). Cannabinoid pharmacology in the cardiovascular system: potential protective mechanisms through lipid signalling.. Biological reviews of the Cambridge Philosophical Society, 79(1), 187-205.