The cannabis plant contains more than 80 different molecules known as cannabinoids, each of which reacts differently within the human body. THC and CBD (cannabidiol) are the two most prevalent cannabinoids found in cannabis. THC makes up 12 to 27% of the cannabinoids in most strains, while CBD makes up 0.1 to 4%.
The most common side effect of THC – psychoactivity – produces the “high” sought by recreational, and some medicinal, users. Cannabidiol, however, does not cause a psychoactive effect, and can even counteract it.
Due to cannabis being used largely for recreation in the past – especially in North America – many cannabis strains have been bred specifically to contain high levels of THC, and low levels of CBD (for minimum interference with this high). But the latter has medicinal uses as well; in recent years, more growers have begun breeding cannabis strains high in cannabidiol, and low in tetrahydrocannabinol. These “medical marijuana” strains can have as much as 12% CBD.
- CBD is more prevalent on the leaves of the cannabis plant than in the buds. These cuttings are often used in edibles; as a result, edibles can be higher in CBD than bud-only ingestion methods (smoking or vaporizing).
- Edibles may also have more cannabidiol due its higher burn threshold. The CBD on the leaves and buds better withstands the temperatures necessary to bake the food.
- In addition to counteracting the psychoactive effect of THC, CBD is also thought to reverse lethargy, another common side effect. Often, the cannabis strains said to increase alertness have higher levels of CBD.
- Despite the lack of mind-altering effects, legally cannabidiol-rich plants are treated the same as all cannabis: as a Schedule I drug in the United States, and a Schedule II drug in Canada.
What Are the Effects of CBD?
Many of the conditions cannabidiol can treat are those already associated with medical marijuana use, though some users may not realize it is this secondary cannabinoid that offers, or enhances, many of these benefits.
- CBD can reduce nausea and vomiting.
- As mentioned above, cannabidiol diminishes psychosis, including memory impairment and paranoia often caused by THC (side effects unappealing to some medicinal users).
- CBD serves as an anti-inflammatory, an anti-oxidant, and an anti-depressant.
- The lack of a traditional “high” does not mean CBD won’t affect the body in any way; it usually creates what is described as a “body high”.
- CBD may be helpful in fighting cancerous cells; some doctors believe it will have a curative effect on breast cancer.
- Cannabidiol has been found to reduce the number of seizures suffered by people with epilepsy, most notably a treatment-resistant type of pediatric epilepsy, Dravet’s Syndome.
CBD Within the BodyCannabinoids react in the body by binding with certain cell receptors naturally present within the human system. These proteins reside within the body’s cells, and pass information into the cells from outside the cell wall, basically instructing them in how to react.
THC acts on CB1 receptors – which are highly concentrated in the brain, and scattered throughout the central nervous system – and CB2 receptors, which are present in the rest of the body. CBD does not act directly on these receptors.
Instead, it suppresses a fatty acid that breaks down anandamide – a compound naturally existing in the human body, that is strikingly similar to THC. Anandamide also acts on CB1 and CB2 receptors. So when CBD is present, more anandamide – no longer broken down – can bind to its custom-made receptors, leaving less space for the THC, diminishing its effect. Preventing THC from binding also prolongs its presence in the body, however, which means the dampened effects of THC may last longer.
CBD interacts with other receptors in the human body as well, such as the TRPV-1 receptor within the nervous systems. It is in this way CBD can lessen a patient’s perception of pain, and reduce inflammation.
Cannabidiol interacts with the 5-HT1A receptor, on which serotonin also acts. This interaction gives CBD its anti-depressant, anti-emetic, and anti-anxiety effects. It does this by slowing down the cell response, where other drugs, such as LSD, speed up the cell response.
The Combination of THC and CBDThere is much discussion in the medical research community regarding whether THC and CBD must be present together in order for each cannabinoid to work to its greatest potential.
Though THC often gets a bad rap from advocates of medical-only cannabis, sometimes being called the “bad” cannabinoid, while CBD is the “good” cannabinoid, the truth is THC offers beneficial medical effects as well. When a strain is high in both THC and CBD, it may offer the medical benefits of both compounds, while minimizing or negating the psychoactive effect unwanted by patients.
Some preliminary research suggests cannabidiol may be more useful as an anti-inflammatory when it is combined with THC. Together, the two cannabinoids may do more to reduce the size and count of tumor cells, and aid neuropathic pain. Essentially, advocates argue using the entire cannabis plant offers a more holistic treatment than extracts or synthetic pharmaceuticals can provide.
If this THC-CBD partnership turns out to be as beneficial as some researchers believe, the legal, pure cannabidiol products now available on the market in many countries may prove to be less effective than those in which a bit of THC still remains.
Research into CBD
During much of the 20th century, as cannabis was being researched, THC was thought to be the only compound of note, with CBD playing a largely inferior, even non-existent role. Then a pharmaceutical company in Europe began researching this little-known cannabinoid. Additionally, people with epilepsy began reporting a decrease in seizures when they inhaled cannabis.
Researchers have barely cracked the surface, however, due largely to the fact that it is difficult to get permission for human trials. There is still much to be learned about CBD and its effects, and whether it works best on its own or in conjunction with other cannabinoids.
Recently, the FDA did approve a trial for patients with epilepsy, using a drug said to be more than 98% CBD, extracted from high-cannabidiol plants.
Cannabidiol oils and tinctures are popular in some regions, and are often presented as a superior option to the buds of the cannabis plant. Unless very scientific, complex processes were used to extract the CBD, however, it is extremely difficult to completely remove other cannabinoids from the product. This means patients purchasing “pure CBD” products from less reputable sources may be ingesting THC and other cannabinoids as well.
This is not to say pure, natural CBD products do not exist. The high-CBD strain Charlotte’s Web has been used to create a concentrated substance that causes no psychoactive effect, and has been found to greatly reduce the number of seizures suffered by patients with Dravet’s Syndome. Some other products billed as 99% cannabidiol do exist.
Unlike THC, CBD can also be derived from hemp plants (which, in order to be legal in the US, and some other countries, must have less than 0.3% THC), though the level of the cannabinoid is very low. Hemp does not flower (create buds), so any CBD must be taken from the leaves and stalk. There is no cannabidiol in hemp seeds, or the hemp “hearts” commonly used as a health food.