As it stands, cannabis has proven beneficial to one’s health in too many ways to list. The cannabinoids contained in cannabis exert their myriad of health effects in particularly gentle ways, and unlike most other pharmaceuticals, cannabis appears to have no toxic limit in healthy adults. Even so, frequent consumers of cannabis may wonder: is inhaling the smoke of anything, even cannabis, good for my lungs? Am I causing long-term damage similar to smoking cigarettes?

The short answer: yes, you should avoid inhaling smoke or any burning material as much as possible. The lungs were not made to filter smoke continuously or really at all. For this reason, previous articles on the blog have discussed vaporizers and the importance of using non-combustive methods of consumption (edibles anyone?). Vaporizers not only improve taste of cannabis, but also virtually eliminate damage caused by smoking. Furthermore, vaporizers are generally able to glean a greater medicinal effect from a smaller amount of cannabis. Frequent users should find the financial investment a no-brainer.

However, clever readers may also wonder: aside from the physical reality of inhaling burning material, what effects do cannabinoids actually have on the lungs? As it happens, cannabinoid research points to an overwhelmingly positive relationship between cannabinoids and lung health. In fact, while we are generally cautious of making strong statements, this is one area where we can be reasonably certain that the long-term effect of cannabis consumption is positive, at least from the properties inherent in cannabinoids themselves. A September article from the medical journal, Frontiers in Pharmacology, has created a well-rounded view of cannabinoid-related lung research. While we’d encourage readers to read it first hand (Title: “Impact of Cannabis, Cannabinoids, and Endocannabinoids in the Lungs” by Caroline Turcotte, et al.), we’ve taken the liberty to summarize the largest areas below.

The largest area of research, inflammation, should not surprise readers. Inflammation is a natural human body response that attempts to limit further damage in the presence of injury or chemical aggravation. Unfortunately, often inflammation is more harmful than helpful, making joints tender (arthritis) or leading to tissue swelling that causes pain and damage. Cannabinoids across the board signal an anti-inflammatory reaction, blocking the accumulation of inflammatory molecules. “The Impact of Canabis…” report cited six studies with cannabinoids ranging from phytocannabinoids found in plants (such as THC), to synthetic cannabinoids created in labs (such WIN55, 212-2), and finally to endocannabinoids produced naturally in the human body (such as anandamide). In all cases, the cannabinoids decreased pro-inflammatory cytokine molecules, reduced Tumor Necrosis Factor Alpha, and in one study, decreased mortality. These anti-inflammatory properties hold true in models of both chronic and acute inflammation, meaning that in general, cannabinoids are helpful to restoring lung function in cases of inflammation.

The second largest area of research, immune function, presents a more complex and interesting picture. Firstly, neutrophils, one of the most common white blood cells, seem to be particularly responsive to cannabinoids. While we are currently unsure how these effects are signalled, cannabinoids have been shown to stimulate antimicrobial peptide release from these cells as well as protective lipid synthesis. In a similar manner, cannabinoids have been shown to play a role in eosinophil (another type of white blood cell) function. Eosinophils are particularly geared toward resolving asthma and allergy reactions in the lungs and congregate at lung sites exposed to allergens or irritants. How effectively they mitigate negative reactions depends on how quickly they are able to congregate. The common endocannabinoid, 2-AG, has been shown to be a “chemoattractant” in live-animal tests, meaning it helps signal for eosinophils to gather. Taken together, these both represent ways in which cannabinoids boost immune function in the lungs.

Unfortunately, the effect of cannabinoids on immune function is not entirely positive. While cannabinoids can help prevent migration of cancer cells, they also slow migration of immune cells. More than that, cannabinoids seem to reduce immune cells’ abilities to fight off lung infections. While it is difficult to model natural lung infection in live animals, we see several signs that the immune system is less prepared to defend against infection in the presence of cannabinoids. First, bacterial load in the lungs remains higher, indicating fewer bacteria are being eliminated by the immune system. Secondly, macrophages that eat and destroy bacterial infection are expectedly lower. Finally, pathogen clearance (not just bacteria) is slower and more problematic. Readers should note that in all cases, cannabinoids were injected rather than inhaled, meaning that these effects are not side effects of the smoke itself but actually effects of cannabinoids on the lung immune system. This seems to be an inevitable property of cannabinoids: while in some cases, the reduction of aggressive cell function is helpful (as in tumors), in other cases, it can be harmful (general immune function). For this reason, patients suffering active lung infection and other types of infections that weigh heavily on white blood cells should refrain from cannabinoid use and consult a physician in regards to treating conditions generally treated by cannabis.

All in all, cannabinoids exert positive influences on lung function, with the exception of immune function. It stands to reason that long-term cannabis users may not suffer long-term effects of consuming cannabis, especially where vaporizers are used as the primary method of consumption. However, we especially look forward to seeing the results of long-term studies designed to compare frequent cannabis users’ lungs to non-users’ lungs. In the meantime, we can be confident that the effects of consuming cannabis are minute compared to the dangers of consuming tobacco. Political pundits seeking to equate the two to support anti-drug policy are comparing apples to oranges or essentially, “blowing smoke” at an under-educated populace.

 

Works Cited

Caroline Turcotte, Marie-Renee Blanchet, Michel Laviolette, et al. Impact of Cannabis, Cannabinoids, and Endocannabinoids in the Luungs. Frontiers in Pharmacology (2016) 7:317. DOI: 10.3389/fphar.2016.00317.