Inflammation is our body’s natural response to infection and injury – without inflammation, our immune system would not be able to deliver white blood cells and other compounds essential to the healing process.
In a healthy inflammatory response, the inflammation is triggered, gets in and does its job, and then goes away, however chronic inflammation is when this inflammatory response remains heightened for a prolonged period of time.
Chronic inflammation is tied to the pathologies of numerous health conditions, and finding natural ways to reduce inflammation is of crucial importance for our health and wellbeing.
Numerous studies have been conducted on the anti-inflammatory effects of cannabidiol (CBD). In this article, we will review chronic inflammation and reference scientific studies to allow the reader to answer the question, does CBD oil help to reduce inflammation?
Growing evidence shows that chronic inflammation both causes and advances many common diseases, with a possible linkage to all disease states. (2)
Under normal conditions, our immune system is a source of reactive oxygen species (ROS) that are capable of fighting off pathogens and initiating tissue repair. These same ROS will begin to cause damage to our tissues and organs if the immune response and related inflammation do not return back to normal levels quickly. (4)
With the commonality of chronic inflammation in such a wide variety of diseases, including infectious disease, cancer, and autoimmune disorders, it is possible that drugs or natural substances that work to reduce inflammation may be of benefit to those suffering from a very wide variety of conditions.
Extensive research exists that links chronic inflammation to multiple stages of cancer, central nervous system disorders (such as autism and multiple sclerosis), asthma, arthritis, diabetes, depression, the metabolic syndrome, and cardiovascular disease. (2,4)
There are numerous markers of inflammation that can be measured, which can help doctors to determine if someone is suffering from chronic inflammation, as well as assist researchers in measuring the effects of different drugs and natural substances on inflammation.
In 2015 a study was published in Drug and Alcohol Dependence that showed marijuana smokers to have lower levels of inflammation in their bodies when compared to nonsmokers. (1)
The researchers took data from more than 9,000 adults aged 20-59 years old in the 2005-2010 National Health and Nutrition Examination Surveys. Of the participants, roughly 12% said they smoked marijuana at least once in the past 30 days, 48% had smoked marijuana once more during their lifetime, and 40% had never smoked marijuana.
Upon examination of the results, normalizing for age, race, sex, education, alcohol consumption, tobacco smoking, BMI, and income to poverty ratio, the researchers found lower levels of serum C-reactive protein (a measure of inflammation positively correlated with heart disease risk) in those who had smoked marijuana in the last month when compared to those who had never smoked it.
While this study suggests a possible anti-inflammatory effect of smoking marijuana, many more studies are needed to confirm these results, such as studies on patients, epidemiological research, and preclinical studies.
Here we will review what the studies thus far have found when examining the possible anti-inflammatory effects of Cannabis sativa, in particular, that of hemp oil products.
Both industrial hemp plants and medical marijuana plants belong to the same genus and species of the Cannabis sativa plant.
These plants have been bred for different purposes, leaving marijuana plants much higher in THC (tetrahydrocannabinol) concentration and hemp plants much higher in CBD concentration.
Both CBD and THC belong to a class of compounds known as cannabinoids, with over 80 cannabinoids found in the Cannabis sativa plant. CBD and THC are the two most abundant and extensively studied of these compounds.
They both exert their effects on the human body partly through their interaction with our endocannabinoid system (ECS). The ECS is a complex system which plays a part in a wide variety of physiological processes, such as mood, appetite, the immune response, and pain sensation. (4)
The ECS is made up of endocannabinoids, cannabinoid receptors, and enzymes responsible for the degradation and synthesis of these endocannabinoids.
Endocannabinoids are cannabinoids that are produced within our bodies. Anandamide (AEA) and 2-arachidonoylglycerol (2-AG) are the two most bioactive endocannabinoids, although others exist.
Cannabinoid receptors are found throughout our central nervous system and peripheral tissues, with CB1 receptors, concentrated mostly in the central nervous system and CB2 receptors concentrated in immune cells and tissues. (3)
The psychoactive effects of THC are thanks to its affinity for the CB1 receptors found in our brains, and the lack of psychoactive effects of CBD is due to its lack of affinity for CB1 receptors.
It is thought that the dysregulation of the ECS may be involved in a wide variety of diseases, with the ECS playing a role in homeostasis, the immune response, and many other crucial functions.
Numerous human studies have found anti-inflammatory benefits of a combination of THC and CBD, including human studies for Sativex, which is an oral mucosa spray of a roughly 1:1 ratio of THC:CBD. (4)
Sativex is an approved treatment for the neuropathic pain and spasticity due to multiple sclerosis, whose pain is linked to chronic inflammation. It has also been found to help reduce the pain of those suffering from rheumatoid arthritis. (4)
As many people exist who suffer from chronic inflammatory diseases but want to avoid the “high” caused by THC, the immunomodulatory role of CBD is of high therapeutic interest.
While more research needs to be conducted on the anti-inflammatory effects of CBD in humans, there exist extensive studies in animal models which support an anti-inflammatory role of CBDs.
In rodent models, CBD has been found to be helpful in the treatment of the pain associated with rheumatoid arthritis, an inflammatory condition. (4,5)
In two studies conducted in 2006 and 2008 by researcher L. Weiss, it was found that CBD was capable of both reducing the initiation and development of diabetes in non-obese diabetes-prone mice through reducing insulitis. (4,6,7)
In these mice, there was a shift in the immune response from a proinflammatory cytokine pattern to one with increased levels of anti-inflammatory cytokines.
In a 2007 study published in the British Journal of Pharmacology, researchers wanted to see if the in vitro neuroprotective effects of CBD in reducing beta-amyloid (A𝛃) neurotoxicity would be replicated in a mouse model.
A𝛃, critical in the pathology of Alzheimer’s Disease (AD), evokes a neuroinflammatory response and is highly neurotoxic. The inhibition of A𝛃 by CBD was confirmed in this animal model, demonstrating an anti-inflammatory effect of CBD on mice with AD.
Even more studies on mice and rats outlining anti-inflammatory benefits of CBD include the reduction of carrageenan paw edema in rats, reduced joint inflammation in a mouse model of arthritis, anti-inflammatory effects on mice with acute lung injuries, reduction in inflammation pain in rats, decreased inflammation in mice with acute pancreatitis, and reduced intestinal inflammation in mice. (10,11,12,13,14,15)
With so many preclinical trials demonstrating therapeutic potential for CBD hemp oil products as powerful anti-inflammatory agents, there remains a need for double-blind, placebo-controlled trials on humans to see if these results carry across species, as well as to provide guidance on the most beneficial dosage for differing conditions.
One of the key aspects of CBD when it comes to inflammation is its ability to modulate the function of the immune system.
While the exact mechanism of how this works and at what concentrations isn’t fully understood, CBD has been shown to inhibit the maturation, proliferation, and migration of immune cells, humoral response, and antigen presentation. (4)
Even though CBD has a low affinity for both CB1 and CB2 receptors, it has been shown to function as an antagonist of cannabinoid receptor agonists when in the low nanomolar range, acting as an inverse agonist at the 1-10µM range. What this means is that CBD acts to inhibit cannabinoid receptor agonists, such as other cannabinoids.
Additionally, it has been found that CBD inhibits fatty acid amide hydrolase (FAAH), an enzyme responsible for endocannabinoid breakdown. This is tied to an increase in the endocannabinoid AEA.
An in vitro study found that CBD suppresses tryptophan degradation. Tryptophan is a precursor to serotonin, and decreased levels of tryptophan have been tied to diseases with immune activation and inflammation. These diseases lead to increased risk of depression, leading to the possibility that CBD could help here as well.
Currently the understanding of how CBD works is still in its infancy, however, as you can see, CBD exerts therapeutic effects through a variety of mechanisms.
Based on in vitro and preclinical animal trials, CBD does appear to have anti-inflammatory potential.
Much more research is needed to understand what therapeutic benefits CBD oil has for inflammation, how exactly it works, and what the ideal dosage may be based on condition and other factors.
1. Cannabis smoking and serum C-reactive protein: A quantile regressions approach based on NHANES 2005-2010.
2. Hunter, P. The inflammation theory of disease. EMBO Reports. 2012; 13(11): 968-970
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