Cannabis has been used worldwide to treat pain for centuries, with the first recorded use occurring in China in 2900 BC. Interestingly, the Chinese used cannabis seeds which naturally contained a low level of THC (delta-9-tetrahydrocannabinol), the intoxicating compound in marijuana – indicating that something other than THC was contributing to marijuana’s pain-relieving effects. Scientists have recently discovered that it is in fact a compound known as CBD which is responsible for marijuana’s pain-relieving effects.
What Causes Pain?
Pain is one of our body’s senses that serves as a signal to the brain of tissue injury or other insult to the body. Special receptors called nociceptors react to chemicals released during tissue damage, such as a burn or puncture wound. Nerve damage can also cause a type of pain called neuropathic pain, such as when a diabetic suffers nerve damage to the nerves in the hands and feet. Finally, there is centralized pain in which the central nervous system (brain and spinal cord) react to unclear causes, resulting in chronic, hard-to-diagnose pain conditions such as fibromyalgia.
Pain is often accompanied by inflammation, which is why people usually reach for NSAIDs in response to pain. NSAIDs treat pain by blocking the inflammatory response. However, NSAIDs don’t work for all people and all types of pain. Pain, particularly chronic pain, is associated with alcohol abuse and opioid abuse, two large public-health problems with high medical costs. Thus, there is a need for alternative methods for treating chronic pain.
How Can CBD Help With Pain?
Animals studies have shown that administration of CBD can act as an immunosuppressant, which decreases the amount of inflammation and associated pain. CBD was particularly effective at reducing pain, inflammation, and cartilage loss in mouse models of arthritis (arthritis is a common cause of chronic pain). CBD has also been shown to reduce pain associated with surgical incisions in rats. And in a rodent model of chronic neuropathic pain, CBD was able to reduce pain levels in rats with sciatic nerve injuries.
Why Care About Animal Studies?
Unlike scientific studies in humans, studies in animals can be much more controlled. Scientists can control most of the non-experimental variables, such as type of food eaten, exercise activity, daily sleep schedules, etc. which cannot be effectively controlled in a group of humans. Animals, especially mammals, also have anatomy and physiology very similar to our own.
It is thought that CBD works to help alleviate pain by reducing the pain signals in the body’s nerve cells. CBD can actually block some nociceptors and increase the pain-inhibitory signals of the central nervous system. CBD can bind to several receptors (in the TRPV, TRPA, and TRPM families) which allows it to mediate and reduce the pain response. Interestingly, CBD can also cause the body’s opioid receptors to be more sensitive, which allows it to amplify the body’s own endorphin response and to help treat opioid addiction. CBD also binds to several other targets in the immune pathway, further amplifying its anti-inflammatory and analgesic effects.
All in all, animal studies have confirmed that CBD’s anti-inflammatory response is several hundred times stronger than aspirin, a common NSAID.