Inflammation is a normal part of the body's immune response, occurring when the body tries to protect itself by removing harmful stimuli and allowing the healing process to begin. Harmful stimuli include damaged cells, pathogens or irritants, and symptoms of inflammation include tissue swelling, redness, numbness, pain and heat from the site of the stimuli. While inflammation is part of a healthy immune system, chronic inflammation is the outcome of a dysfunction or disruption of those bodily signals.
There are multiple types of inflammation, characterized by length and severity. Jamming a finger in the door causes immediate pain and acute inflammation, but both short-lived. In response to this harmful stimulus, the immune system kicks in by sending an army of white blood cells and other necessary substances to initiate the healing process. By contrast, chronic inflammation is a state of persistent stimuli, which may be triggered by anything from a lingering infection to allergies. A malfunction of the healthy immune response could also result in an autoimmune disease, whereby the immune system mistakenly attacks the healthy cells in the body.
Chronic inflammation can last for years, and is a major factor in numerous autoimmune ailments such as multiple sclerosis, lupus, arthritis and colitis. According to the National Institutes of Health (NIH), there are more than 80 types of autoimmune disorders, and the current immunosuppressive medicines used to treat them tend to cause severe side effects.
In 2009, the NIH published a review of collated reports on the anti-inflammatory activities of cannabinoids, one of the compounds in medical marijuana, with regards to its effects on inflammation. The report revealed that cannabidiol (an abundant non-psychoactive cannabinoid in marijuana), reduced joint inflammation in collagen-induced arthritis.
The cannabinoid receptors in the body, mainly the cannabinoid receptor 2 (CB2), are targeted by the cannabinoids in medical marijuana. When the receptors are activated, they release fewer cytokines (pro-inflammatory mediators).
Beta-caryophyllene is the main substance in medical marijuana that helps control inflammation. Medical marijuana's essential oils are composed of between 12 to 35 percent of Beta-caryophyllene, which has been shown to decrease inflammation by up to 70 percent in the animals tested. Available research strongly indicates the efficacy of medical marijuana as a means of decreasing inflammation.