A comprehensive review challenges the perception of cannabis as harmless, linking it to severe heart health issues.
Study: The relationship between cannabis and cardiovascular disease: clearing the haze. Image Credit: Nicole Piepgras/Shutterstock.com
Against the global backdrop of escalating cannabis use, a recent review published in Nature Reviews Cardiology reviews current knowledge on the effects of cannabis consumption on the human cardiovascular system.
They study the different types of cannabis—both traditional/organic and synthetic—along with the receptors they interact with, their mechanisms of action, and their links to cardiovascular risk factors, including cardiomyopathies, atherosclerotic cardiovascular disease, and arrhythmias.
Their findings reveal that contrary to the public perception, mounting epidemiological evidence emphasizes that cannabis is not harmless, linking the drug to severe cardiovascular complications. These findings are critical to informing users, citizens, and policymakers of the potential harms of cannabis use in today's increasingly cannabis-tolerant world.
Background
Cannabis is a generic term to describe chemically non-uniform drugs derived from the Cannabis sativa plant. Colloquially termed 'weed,' 'marijuana,' 'ganja,' and 'pot,' cannabis is native to Central and South Asia and has been used for both recreational and medicinal purposes for thousands of years.
The World Health Organization (WHO) estimates that currently, 147 million people (~2.5% of the global population) consume cannabis recreationally via modalities including smoking, vaping, hookah, and edibles.
Despite its global use being substantially arrested via government prohibition, the United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances (1988) triggered a policy reversal, resulting in escalating and ongoing legalization and decriminalization of the drug's use.
Currently, public perception supports cannabis use, deriving from the belief that cannabis and its numerous components (cannabinoids) are medically safe.
Unfortunately, a mounting body of epidemiological evidence challenges this notion, highlighting several medical risk factors associated with cannabis.
About the review
The present review traces the evolution of global cannabis regulation and use, highlighting how recent policy changes, decriminalization, and legalization have substantially increased cannabis accessibility and consumption.
It elucidates key cannabinoids and their interactions with the endocannabinoid system and cannabinoid receptors.
It emphasizes the limitations of historical research and their role in shaping current public perception of cannabis safety, using recent epidemiological evidence to highlight that cannabis and its derivatives can severely hamper human cardiovascular functioning.
Finally, it distinguishes between traditional/organic cannabis and synthetic cannabinoids, comparing the medical demerits of both to educate public opinion and policymakers.
A brief history of marijuana
Cannabis has been a popular recreational drug in Central and South Asia for thousands of years. The drug was introduced to the West in the 13th and 14th centuries, but global prohibition movements (20th century) made its consumption illegal.
The United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances (1988) and the compassionate use of medical cannabis as a painkiller have slowly changed public and government opinion, with more than 40 nations now allowing medical marijuana consumption.
Notably, ten nations (Netherlands, Georgia, Canada, Luxembourg, Mexico, Malta, South Africa, Uruguay, and Thailand) have legalized recreational cannabis consumption, and potentially more countries will follow suit soon.
This has significantly increased cannabis consumption, with the United States alone generating ~US $ 54 billion per year from legal cannabis sales.
Cannabinoids and the human body
Cannabinoids are the active components (n = ~100) of cannabis (~500 compounds), with Δ9-Tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD) being the most abundant and best studied.
Cannabinoids elicit psychoactive and therapeutic effects on humans predominantly via their actions on specific G protein-coupled receptors (GPCR) called cannabinoid receptor 1 (CB1; brain and vasculature) and CB2 (immune cells and vasculature).
Under normal conditions, naturally circulating endocannabinoids bind to these receptors, regulating hemodynamic effects (heart rate, blood pressure, vascular tone, and myocardial contractility) and regulating immune cell inflammation.
When consumed, cannabis-derived 'endocannabinoids' bind to these receptors in dose-dependent manners, potentially resulting in pro-inflammatory responses, stress signaling, oxidative stress, fibrogenesis, and cell death.
Furthermore, given the role of the endocannabinoid system in mood, learning, and behavior, recent evidence highlights the role of excessive cannabis consumption in endocannabinoid system dysregulation, resulting in obesity, type 2 diabetes, metabolic syndrome, hypertension, and dyslipidemia.
Several preclinical and clinical trials have revealed the associations between cannabis consumption and subsequent arrhythmias, cardiomyopathy, and other cardiovascular diseases.
Synthetic cannabinoids
Traditional cannabinoids comprise CBD, THC, and similar cannabis-derived compounds, consumed and studied for their recreational properties and potential as therapeutics and pharmacologicals.
Research aimed at better understanding medical marijuana resulted in the development of 'synthetic cannabinoids' such as CP 47,494 and JWH-018.
Unfortunately, newer, often illegal, recreationally-aimed versions of synthetics (AB-FUBINACA, MDMB-FUBINACA, and ABM-FUBINACA) have begun infiltrating the market.
Procured under the street/trade names of 'K2' and 'Spice,' these cannabinoids are substantially more potent than their organic counterparts, having been reported to cause respiratory depression, neuropsychiatric trauma, and death.
"To resolve remaining uncertainties and better inform policymakers and the public, the effects of cannabis and natural and synthetic derivatives on the cardiovascular system need to be rigorously investigated."
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