Cannabis interacts directly with a system in our body that helps regulate our immune responses and we know that it can be helpful in treating auto-immune diseases. It is not necessarily as helpful when it comes to fending off viruses and other pathogens, however.
What cannabis does to the body
Chemicals in the cannabis plant like THC and CBD, called, cannabinoids, interact directly with the body’s endocannabinoid system. These chemicals mimic natural chemicals the body produces, all of which can trigger a wide variety of effects on functions like sleep, hunger, pain and mood.
Part of the endocannabinoid system’s role is to maintain homeostasis or balance of the immune system. While the literature contains some contradictions on how exactly that works, it is generally considered a “gate-keeper” of the immune system — preventing it from causing overwhelming inflammatory responses.
Suppressing the immune system may make cannabinoids helpful in conditions where immune responses turn against the patient’s own body. Indeed, many autoimmune conditions, such as rheumatoid arthritis, multiple sclerosis, and diabetes, have already been tied to dysregulation in the endocannabinoid system.
Still, in cases of infection from pathogens, researchers warn that these immunosuppressive effects could be problematic — suppressing the body’s natural and needed immune responses.
Research on cannabis for immune health
While our theoretical understanding of the endocannabinoid system suggests that cannabis could suppress important immune responses, thereby increasing our susceptibility to infectious diseases, the research actually presents a more complex picture.
Beyond treating autoimmune conditions, suppressing immune responses can in some other situations be desirable when dealing with certain infections. When under attack from an infection our bodies sometimes go into sepsis — producing a systemic inflammatory response that can lead to death. Reducing this response could be live-saving.
Research on animals shows that stimulating endocannabinoid receptors with cannabinoids like those in cannabis can reduce infection-related inflammation, in some cases also reducing the overall death rate. Some studies also showed it improved recovery for infections like malaria.
In other animal experiments, reducing stimulation of these same receptors led to increased survival from infection. And in some experiments stimulating these receptors decreased immune response against infections like candida, legionella pneumophila, and influenza.
These animal studies present a somewhat conflicted picture, and human studies have been extremely limited.
Potential benefits and harms
Interestingly, in spite of the data from animal studies, early double-blind, placebo-controlled human studies found no immunological alterations observed with THC use. Later though, some immunosuppressive effects were found in the human research. Notably though, in the same study, this effect reversed in two patients who had long term exposure to cannabis. So it’s possible that the long term effects of cannabis may differ from acute use when it comes to immune response.
Still, while researchers have found immune differences in humans from cannabis use, they haven’t confirmed that these alterations make cannabis users more susceptible to infection.
So, while in some ways cannabinoids show promise for treating viral infections (such as reducing sepsis), they can also pose risks like suppressing needed immune responses.
Researchers report that cannabinoids do have potential as treatments for infectious disease but say we need much more research to learn exactly how to use them in a way that ensures they are helping and not hurting our chances against an infection. Until more research is done, we really can’t say for sure.