Due to the recent Covid-19 pandemic, there are many people wondering how cannabinoids affect the immune system as a number of companies are making claims about using cannabidiol (CBD) to help fight viral infections. Golden, Colorado-based Panacea Life Sciences answers some common questions.
Do hemp products assist or weaken the body’s ability to fight off an infection? The question of whether cannabis or hemp products assist or hurt the body’s ability to fight a viral infection is complicated for a number of reasons. Due to the intricacy of the immune system, the number of components in full-spectrum hemp or marijuana products and the relatively few scientific studies and articles that provide definitive answers to these questions are hard to come by. To understand how cannabidiol may be a potential supplement to help the immune system, it is first necessary to have a basic understanding of the immune system, the Endocannabinoid System (ECS), and how cannabidiol influences these systems.
Overall, the research does not support strong anti-viral activity of CBD. Instead, CBD and other cannabinoids may provide benefit in fighting secondary infection through its reported anti-bacterial properties and easing aches and pains associated with flu-like symptoms.
How does our immune system combat infection?
Figure 1, above, shows a simplified description of our immune system. The immune system is very complex, consisting of several organs and cell types which are needed to fight off a variety of infectious agents including viruses, bacteria, molds and parasites and can be reviewed in more detail here. The body provides a physical barrier through the skin and mucous membranes that prevent infectious agents from entering.
If a virus, for example, enters through a cut in the skin or penetrates mucous membranes, then the first line of defense, termed the innate immune system, identifies the intruder then and directly attacks to destroy and eliminate or immobilize the infectious agent. A specific response tailored to the infectious agent through the adaptive immune system is also activated, but this takes a bit more time to generate antibodies and specific T-cells.
The Endocannabinoid System (ECS)
Discovered in the late 1980s, the ECS was first thought to be comprised only of the Cannabinoid 1 (CB1) and Cannabinoid 2 (CB2) receptors that are located throughout the body, as shown in Figure 2. Scientific knowledge of the ECS system has expanded to include as many as 50 receptors and enzymes that interact with various cannabinoids. The large and varied number of targets cannabinoids interact with explains the number of conditions or biological processes the ECS influences. While there is much to be learned about the ECS, the system appears to function as a regulator of various physiological functions to return the body back into balance or to normalize biological responses, termed homeostasis. In the case of the immune system, the ECS dampens the inflammatory response to lessen the possibility of dysregulation.
Cannabinoids and the Immune System
Our bodies produce endogenous cannabinoids, termed endocannabinoids (within the body), that regulated the ECS. Two identified cannabinoids, Anandamide (AEA) and 2-Arachidonyl Glycerol (2-AG), are produced in the body to help maintain correct body function. As stated earlier, there are a small number of studies published on the effects of cannabinoids on the immune system, and those that have been published do not provide a clear picture of action.
Cannabinoids appear to affect the immune system primarily through the CB2 receptor. This receptor is expressed on multiple immune cells and when activated by cannabinoids, decrease overall inflammatory responses. While studies consistently conclude that cannabinoids and activity at the CB2 receptor suppress inflammation and immune function, there appear to be differential activities amongst both endogenous (e.g. Anandamide or 2-acrachidonoylglycerol) and phytocannabinoids (cannabinoids introduced to the body that are derived from marijuana plants) on the immune system overall.
Anandamide (AEA) affects cellular communication amongst immune cells by lowering the expression of several immune proteins. Whereas AEA exhibits an inhibitory effect on immune function, 2-acrachidonoylglycerol (2-AG) augments immune function by increasing the release of nitric oxide (used to destroy target cells) to increase immune cell activity. The differential responses by these endocannabinoids are most likely mediated through receptors and/or enzymes distinct from CB2 that have not yet been fully described.
Similarly, THC and CBD exert overlapping yet distinct effects on the immune system. Much of the information regarding THC stems from studies in human immunodeficiency virus (HIV) infected patients. In HIV patients, THC has been reported to reduce morbidity, increase gut mucosal immunity, reduce lymph node fibrosis and lower viral counts. However, THC also has been reported to decrease resistance to a variety of other infectious agents such as the Listeria monocytogenes, Mycobacterium tuberculosis, genital herpes and herpes simplex virus 2.
The collective data suggests that THC inhibits the functional activities of a variety of immunological cells needed to combat infection and that the outcome is consistent with decreasing host resistance to infectious agents, which may enhance disease progression and in the worst cases, lead to death. Like THC, there are few studies on the effects of CBD on the ability to boost the immune system to combat viral infections. CBD has been reported to reduce replication of Hepatitis C and Karposi’s sarcoma associated viruses but was not effective in inhibiting hepatitis B virus replication.
Clearly, scientific data does not yet conclusively demonstrate whether cannabinoids are effective at boosting the immune system to help combat viral infections. If anything, THC may increase risk for infection and has been shown to be a risk factor for Mycobacterium tuberculosis (TB) infection. Any claims regarding the use of cannabis or industrial hemp products to combat viral infection by cannabis manufacturers is false and misleading. The Food and Drug Administration has issued warning letters to four CBD manufacturers who are making claims of CBD successful in treating COVID-19 infections.
Where cannabidiol can help: secondary infection ease of aches and pains
Viral respiratory tract infections (VRTIs), such as the flu and the coronavirus are quite common, with presentations varying from simple colds to life-threatening infections. During a viral infection, the virus debilitates the body’s mucociliary clearance structure which leads to the increased attachment of bacteria to mucins and colonization occurs. The mucus build-up impedes the penetration of antibacterial material and immune cells, and therefore, bacterial coinfection occurs in up to 60 percent of VRTIs. During the 1918 flu epidemic, it was estimated that of the 50 million deaths, many were due to secondary bacterial pneumonia with Streptococcus pneumoniae.
At the 2019 American Society for Microbiology Microbe, Dr. Mark Blaskovich reported that cannabidiol possessed gram-positive antimicrobial activity with potencies similar to antibiotics vancomycin and daptomycin. The report also stated that cannabidiol did not lose effectiveness with repeated applications, as seen with other antibiotics, and had the ability to dissolve biofilms produced by gram-positive bacteria.
A subsequent study at the University of Southern Denmark demonstrated that cannabidiol is an effective “helper” compound that, when used in combination with bacitracin, an antibiotic, increased the effects of bacitracin to kill gram-positive bacteria, including antibiotic resistant bacteria.
Although clinical studies should be conducted, these findings suggest that CBD may be effective at preventing or treating gram-positive secondary infections subsequent to VRTIs. Additionally, inclusion of CBD in soaps for surface or hand cleaning may help lower the incidence of infection by gram-positive bacterial (such as staphylococcus species) in settings where these bacteria are prevalent (such as in hospitals).
Scientific evidence regarding CBD’s effectiveness in stimulating the immune system’s ability to combat viral infection is disparate and inconclusive. Specific studies need to be conducted to determine whether CBD is effective at helping immune cells resist or minimize infection to influenza or cold viruses. In many cases, cannabinoids may exacerbate the condition, especially if dosed by inhalation. Any company representing CBD products as effective antiviral treatments is making false claims and will be subject to FDA warning letters and possible product recall due to these claims. The true value of CBD for those ailing from a viral infection is its ability to ease the aches and pains, such as a sore throat, caused by the viral infection and to protect and combat secondary bacterial infections.