With its mysterious array of symptoms and unpredictable effects, COVID-19, the illness caused by the novel coronavirus SARS-CoV2, continues to puzzle scientists around the globe.
As researchers work to develop vaccines and life-saving treatments, new studies are revealing some intriguing connections between cannabis and the processes driving some of COVID-19's most devastating outcomes.
Here's what we know so far about the potential for cannabis compounds and terpenes to ease this new and challenging disease's symptoms.
Unraveling the Mystery of COVID-19
Since the world first learned of a new, or novel, coronavirus in early 2020, researchers have been struggling to understand how it works- and why it can cause symptoms ranging from mild loss of smell to severe respiratory distress and even death.
Although this coronavirus is new to humans, it belongs to a larger family of viruses that we already know all too well. Coronaviruses are responsible for many of the colds and flu that make the rounds every year.
COVID-19 is a relative of another virus that caused widespread illness a few years ago, called SARS – an acronym for Severe Acute Respiratory Syndrome. That's why it has the official name of SARS-CoV2. And the illness it causes is called COVID-19, for Coronavirus Disease 2019.
In the early days of the pandemic, scientists believed that COVID-19 was mainly a respiratory disease. But now, research has shown that SARS-CoV2 affects processes that control many different systems throughout the body.
This information helps explain why it can damage the heart, lungs, and other organs and why it can also cause circulation problems, brain fog, and a loss of taste and smell. These symptoms all arise from the virus's interaction with a single protein on many cells' surface – the angiotensin-converting enzyme 2, better known as ACE2.
ACE2: the Gateway to COVID-19
ACE2 is an enzyme that plays a major role in the health of the cardiovascular system and lungs. It's formed from a chain of activity in the renin-angiotensin-aldosterone system, which plays a crucial role in regulating the body's blood volume and vascular resistance.
These factors work together to influence the heart's pumping output and pressure in blood vessels throughout the body. That's why many people with hypertension and other circulatory problems take medications known as ACE2 inhibitors, which may offer some protection against COVID-19 infection.
But ACE2 is also the entry point for SARS-CoV2, which takes over receptors on the surface of ACE2 cells. ACE2 cells are found in many parts of the body, but they're especially abundant in the lungs and small intestine, which accounts for the many respiratory and digestive symptoms of COVID-19.
They're also common in the vascular endothelium, a cell layer that lines the arteries and veins' walls. That helps to account for the many cardiovascular symptoms associated with COVID-19.
COVID and the Endocannbinoid System
SARS-CoV2 enters the body by way of the ACE2 receptor cells, but it's helped along by a protein on the surface of ACE2 called transmembrane serine protease 2, or TMPRSS2. This protein enables the virus to enter ACE2 cells and bind to their cell membranes so that the virus can increase within the lungs, cardiovascular system, and other organs. This process is the target of many studies on the treatment and prevention of COVID-19.
New research by scientists in Israel and the US indicates a potential connection between the activity of these proteins and the endocannabinoid system, a large network of cell receptors that respond both to cannabinoid chemicals produced by the body and compounds in the cannabis plant. That connection explains why cannabidiol, or CBD, and other cannabis compounds and terpenes may have the potential to treat symptoms of COVID-19.
The Endocannabinoid System: A Key to Fighting COVID-19?
The endocannabinoid system plays a crucial role in maintaining homeostasis or balance, among the body's many subsystems. Endocannabinoid receptors CB1 and CB2 are found in the brain, central nervous system, and many other tissues and organs.
They respond to the expression of natural cannabinoids 2AG and anandamide to support immune function, healthy cell development, and much more. And because they respond in similar ways to cannabis compounds, some researchers think that cannabis could play a major role in the fight against COVID-19.
Cannabis Could Prevent COVID-19 Infection
A Canadian study found that CBD extracts appear to "downregulate" or slow the activity of TMPRSS2. This is the protein that helps the novel Coronavirus enter ACE2 cells. In that way, CBD could prevent SARS-CoV2 proteins from infecting cells at all. Researchers speculate that this discovery could point to the development of simple CBD-based preventatives such as a mouthwash or throat rinse.
Cannabis Might Fight the Cytokine Storm
Cannabis also has anti-inflammatory and immune-supporting properties, and some research suggests that it could play an essential role in fighting one of the most serious complications of COVID-19 – the cytokine storm.
Cytokines are proteins released by the immune system in response to an infection or inflammation. Generally, that's essential for healing. But in some situations, the immune system goes into overdrive, releasing a flood of cytokines into the bloodstream too quickly. Along with attacking the virus, these cytokines attack the body's cells and tissues, causing more inflammation and potentially shutting down the kidneys, liver, and other organs.
But recent research from Israel suggests that cannabis might inhibit cytokines' production, which could reduce the intensity of the immune response without the side effects of strong immunosuppressant medications. Terpenes can boost the effects of cannabis compounds. Scientists from Tel Aviv University and the private sector found that a combination of CBD and terpene extracts could be as effective as dexamethasone, a steroid currently used to treat severe COVID-19 symptoms.
Conflicting Evidence Clouds Outcomes
Although a number of studies suggest cannabis can have considerable benefits for treating COVID-19, some scientists caution that this research is limited and preliminary – and there are also indications that cannabis could be harmful to COVID-19 patients, especially when smoked.
Inhaling heated smoke of any kind can cause inflammation in the lungs and respiratory system cells, making them more vulnerable to infection with SARS-CoV2. Several studies have noted that in general smokers with COVID-19 are more prone to respiratory complications than non-smokers, including people who smoke cannabis. Likewise, some researchers suggest that vaping could also increase the risk of more severe respiratory symptoms of COVID-19.
Research on the benefits of cannabis for COVID-19 is still in the early stages. But recent studies suggest that this ancient remedy could be a powerful weapon against a very new disease.