Does cannabis help or harm the immune system?
Cannabis is today recognised for the benefits it offers in the management of certain medical conditions. As cannabis research develops, consumers are increasingly aware of the therapeutic potential of cannabinoids in the treatment of specific diseases.
But how does cannabis affect the immune system as a whole? Does cannabis weaken or strengthen the immune system. Can frequent cannabis use make you more vulnerable to infections or contagious diseases?
This question has not historically aroused much interest among scientists. Current research suggests that cannabis can decrease the effectiveness of the immune system. While this can be helpful for people with autoimmune diseases, it could be of benefit to people who have functioning immune systems.
Table of Contents
- What is the immune system?
- Cannabis, the endocannabinoid system and the immune system
- How does cannabis affect the immune system?
- The pros and cons of cannabis as an immune suppressant
What is the immune system?
The immune system is one of the most sophisticated networks in the body made up of specialized cells and organs working together to fight pathogens and infections, thereby protecting the health and homeostasis of the body.
The immune system is multifaceted and its main components that actively fight infection include white blood cells, complement system, antibodies, lymphatic system, spleen, thymus, and bone marrow, but we will mainly talk about white blood cells.
Memories of each microbe previously defeated by the immune system are stored in white blood cells. This memory allows rapid tracking and elimination of infections already suffered. The immune system is also responsible for detecting and eradicating defective cells.
Our knowledge of the interaction of cannabis with specific immune elements is limited. While some research explores the effects of cannabinoids on white blood cell counts and the lymphatic system, less is known about the impact of cannabis on the thymus or the complement system.
Cannabis, the endocannabinoid system and the immune system
There is a connection between the endocannabinoid system (SEC) and the immune system. The SEC is generally considered to be one of the guardians of the immune system, preventing the onset of overwhelming inflammatory responses that can lead to disease. SEC can also influence the function of immune cells.
The CB1 and CB2 receptors of the endocannabinoid system modulate the effects of cannabis within the immune system. The two main cannabinoids, THC and CBD, appear to have distinctive effects on the immune system due to their unique interactions with cannabinoid receptors. An abundant literature suggests that cannabinoids affect the functions of most types of immune cells.
A 2020 review of studies showed that CBD suppresses certain inflammatory responses in the immune system and can induce cell death in immune cells. The death of immune cells is not always a bad thing. It is part of the cell life cycle and helps protect a person by reducing inflammatory reactions.
Like CBD, THC also suppresses immune activity, dampening inflammatory responses. THC has also been shown to impair the function of immune cells responsible for antimicrobial activity.
How does cannabis affect the immune system?
Studies linking cannabis and the immune system often rely on the immunomodulatory or immunosuppressive effects of cannabis. Immunomodulation refers to any therapy that changes the response of the immune system. When cannabis suppresses the expression of aspects of the immune system, this form of modulation is known as immunosuppression, which can be helpful if the immune system is deregulated.
A study published in 2017 indicated that CBD and THC have an immunomodulatory effect on the human intestinal lymphatic system, the main host of immune cells. The lymphatic system also contains more than half of the body’s lymphocytes, white blood cells that play a vital role in finding and destroying foreign cells or substances that have entered the body.
The study authors found that oral administration of CBD and THC resulted in extremely high cannabinoid levels in the intestinal lymphatic system: CBD concentrations in lymphatic cells were 250 times higher than in plasma, while that THC concentrations in lymphatic cells were 100 times higher than in plasma.
For people with autoimmune diseases, cannabis can thus reach higher concentrations in the lymphatic system and suppress unhealthy inflammatory immune responses more effectively.
The pros and cons of cannabis as an immune suppressant
Although the immunosuppressive properties of cannabis may benefit some autoimmune patients, they can cause problems for other cannabis users.
Research conducted in 2003 on healthy volunteers suggests that cannabis may dampen immune function with a decrease in the number of pro-inflammatory cells and more anti-inflammatory cells. These changes were associated with a significant reduction in the functionality of white blood cells, and impaired white blood cells may mean a reduced ability to fight infection. Regular cannabis users also had a decrease in the amount of natural killer cells, which limits the spread of tumours and microbial infections.
The study also indicated that there may be a dose-response relationship between cannabis use over an individual’s lifetime and a decrease in certain markers of the immune system, meaning that those who consume cannabis on a regular basis cannabis may be more susceptible to the progression of an infectious disease.
What about the effects of cannabis on people who are extremely immune compromised? Unfortunately, cannabis can drastically reduce anti-invective cells in people undergoing chemotherapy. This suppressive response can further add to the damaging effects of chemotherapy on the immune system of people with cancer.
Research on people with HIV and AIDS, who are particularly vulnerable to infections, however, indicates that there is no strong evidence that cannabis adversely affects immune function.
Instead, the results suggest that cannabis use in HIV-positive patients may improve the immune system by producing a statistically significant decrease in viral load and an increase in CD4 cells. CD4 cells can be considered as a marker indicating the robustness of the immune system.
While existing research allows us to gather information on cannabis and the immune system, we need more rigorous data to paint broad brushstrokes. According to the latest 2017 report from the National Academies of Science, Engineering and Medicine (NASEM), research on the effects of cannabis or cannabinoid-based drugs on the human immune system is insufficient to draw firm conclusions .