Key takeaways.

  • How does cannabis affect the immune system?

    Most cannabinoids have an immunosuppresant action, meaning they tone down the activity of the immune system. This can be useful for those who have pathological immune responses, such as in autoimmune disease.

  • How is cannabis used clinically for its immunomodulating effects?

    Cannabis' immunomodulatory effects can be taken advantage of in autoimmune diseases such as Crohn's disease, Hashimoto's, and even Alzheimer's. Immune dysfunction plays a role in the pathogenesis and progression of all of these conditions.

  • How does this affect the everyday user?

    In one study, researchers found that users had reduced immune responses, but other researchers say it's far too early to understand how cannabis affects the immune system, especially for the everyday user.

One of cannabis’ prized pharmacological activities is its ability to reduce inflammation in those with pathological immune responses. And actually, cannabis’ anti-inflammatory property is just one of a range of different immunomodulatory effects that cannabis can produce. A number of cannabinoids in the cannabis plant work through the immune system in some way, causing a modulation of immune response.

Immunomodulation refers to anything that affects the immune response, whether it’s because it’s immunosuppressive (reduces the immune response), immunostimulant (stimulates the immune response), anti-inflammatory, anticancer, etc. Any medication that affects an immune response is said to have immunomodulatory properties, and when it comes to plant medicine, cannabis is high on the list.

We’re really just in the infancy of understanding how to perfectly use cannabis for its immunomodulatory properties. We know that cannabis has powerful anti-inflammatory properties for those with Crohn’s disease and might use anti-inflammatory mechanisms to reduce depression and epilepsy. But to what degree does the immunomodulatory effect of cannabis affect the everyday user who has no particular pathological immune issues?

In this article, we’re talking about some of the immunomodulatory effects of different cannabinoids, how they can be used in disease, and also how that might affect the everyday healthy user. 

An introduction to your immune system.

An illustration of a deep dissection of the human back and neck showing the vasculature of that area.
Jules Cloquet, 1825.

The immune system is your body’s way of defending itself against pathogens — and even against itself! Your immune system is coded even with anti-cancer genes, knowing that sometimes it needs to switch itself off, otherwise it can make the organism sick. In certain individuals, this “switch off” mechanism doesn’t work, and autoimmune diseases, sometimes cancer, and transplant rejection occurs.

The immune system is made up of different types of white blood cells, lymphatic fluid and lymphatic tissues and organs such as your lymph nodes. Specialized cells investigate the body (T cells) while other specialized police cells hunt down pathogens and destroy them (macrophages). These cells go through a very sophisticated training program called maturation where they learn to identify what’s the host and what’s a pathogen. 

Some immune cells (B and T cells) even have a memory that can last almost a lifetime so that if the organism is infected twice by the same pathogen, it mounts a faster response the second time.

It can sometimes happen that the immune system isn’t able to recognize itself. This happens as a result of defective elimination of self-reactive immune cells. In essence, the human body’s immune system starts attacking its own tissues. Crohn’s is considered an autoimmune disease, as is rheumatoid arthritis, Hashimoto’s, multiple sclerosis, and lupus

Some autoimmune conditions only occur in a certain part of the body such as with Hashimoto’s (affecting the thyroid) and arthritis (affecting the joints). Others become systemic and have a range of symptoms all over the body such as in lupus.

Cannabis’ immunomodulatory effects can be very useful in autoimmune conditions because of its immunosuppressive behaviours. It can also be useful for acute infections and moderating painful immune responses such as injury inflammation. Let’s check out some of the ways cannabis affects the immune system.

How does cannabis affect the immune system?

Like we mentioned, cannabis is currently in the clinical spotlight for its immuno-suppressant effects. Its most exciting use is its potential ability to suppress pathological immune responses that are responsible for disease onset and progression, such as Crohn’s disease. 

There is research to support cannabis as an anti-inflammatory, immunosuppressant, antibacterial, and even possibly antifungal.

But not all cannabinoids possess the same qualities to the same degrees, so let’s have a look at the different immunomodulatory effects of different cannabinoids.

THC — immunosuppressive.

Overall, the research surrounding THC’s effect on the immune system puts it in the immunosuppressive category. It appears that THC suppresses pathological immune responses via the CB2 receptor. Though the exact pathway isn’t known, the endpoints are mediated by CB2 receptor interaction with THC. The result is inhibited T-cell proliferation and reduced secretion of cytokines such as IL-2. 

In clinical observation, researchers have found that THC reduces the pathological immune response associated with colitis and multiple sclerosis in animal models.

CBD — immunosuppressive and anti-inflammatory.

A collage art of kings and queens holding cannabis and other fruits.

As with THC, it’s generally accepted that CBD’s effects on the immune system are immunosuppressive. Interestingly, CBD might not necessarily have these effects because of CB receptors, as CBD doesn’t have a strong affinity for CB receptors. However, CBD has shown to suppress immune response by promoting cell apoptosis, reducing the secretion of inflammatory cytokines, and reducing cell proliferation

These mechanisms by which CBD reduces the immune response are also what make CBD anti-inflammatory. As inflammation occurs as a result of these pathological immune responses, suppressing the immune system results in a decrease in inflammation.

In older research, CBD has also shown bacteriostatic and bactericidal activity (antibacterial). But it might be cannabis terpenes that have more of a role to play when it comes to antibacterial activity.

CBG — antimicrobial.

CBG is a precursor to other cannabinoids, meaning THC and CBD actually form through the biological pathway of CBG. It’s therefore most abundant in “unripe” cannabis. This cannabinoid as been researched for its antimicrobial properties, especially against bacteria.

In one study, CBG showed promising efficacy in destroying the cell membranes of gram-negative bacteria. It was especially effective when it was combined with other antibiotics. CBG also showed a reduction in the bacterial load in the spleen of the murine models used in the study.

It’s important to remember that antimicrobial activity doesn’t necessarily denote immunomodulatory effects, as the antimicrobial activity doesn’t work directly through the immune system. Rather, it works by killing the bacteria. It can be seen as an assistant to the immune system in eradicating bacteria, but doesn’t directly affect the immune system’s behaviour.

How does this affect the everyday cannabis user?

A collage art of cannabis users dancing on cannabis buds with a screen in the background showing the city.

It’s clear that cannabis can have serious implications within the immune system, especially for those with autoimmune diseases or chronic inflammation. But how does this immuno-alteration affect those whose immune systems are otherwise good and functional?

One 2003 study found that regular (otherwise healthy) cannabis users may have subdued immune responses. The healthy volunteers showed fewer pro-inflammatory cells and more anti-inflammatory cells. But they were all healthy at the time of being researched.

The anti-inflammatory status of regular cannabis users might be seen as a benefit or positive, but if the result is fewer circulating inflammatory cells, there could be a decreased resistance to infections. 

At the same time, a 2017 report concluded that there was still far too little research to understand the extent to which cannabis and cannabinoids affect the human immune system. 

Clinical applications for immunomodulatory cannabis.

A collage art of a woman picking cannabis buds off a cannabis plant with the sky in the background.

The clinical applications for cannabis, because of its immunomodulatory effects, are far reaching. For some people, it’s as simple as taking advantage of the localised anti-inflammatory effects of topical cannabis. For others, it’s about reducing inflammation associated with chronic autoimmune diseases.

The most researched clinical applications for cannabis’ immunomodulatory effects are in the treatment of Crohn’s disease, Multiple Sclerosis, Parkinson’s disease, and Alzheimer’s. When cannabis is used in other medical conditions, it’s not necessarily for its immunomodulatory effects.

There is a consensus that the endocannabinoid and immune systems are closely tied together, and there is still ongoing research into how these two systems talk to each other and work together. Through this research, we might be unveiling underlying endocannabinoid or immune dysfunction in diseases we didn’t know were caused by these kinds of dysfunctions.

As it stands, though, cannabis in the clinical context is used for its immunosuppressive qualities. It’s not typically considered an immune enhancer, and is also not recommended for those who are heavily immunocompromised.

Have you used cannabis for any of the immunomodulatory reasons we’ve mentioned in this article? What was your experience like? We’d love to hear from you in the comments!

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