A January 23, 2019 article appearing in MPR came with a provocative title: Medical Cannabis Decisions Being Made by Users, Not Doctors. Quoting a study published online on January 8 in the Journal of Psychoactive Drugs, HealthDay News summarized, “Many patients use medical cannabis without their mainstream health care provider’s knowledge, and further, they self-adjust their pharmaceutical use in response to cannabis use.”
Simply put, many people in the US obtain and use medicinal marijuana by themselves (outside of the healthcare system) and are self-medicating. The authors of the study, Daniel J. Kruger, PhD, from the University of Michigan in Ann Arbor, and Jessica S. Kruger, PhD, from the University at Buffalo in New York, concluded, “Those working in public health and medicine have an obligation to reduce harm and maximize benefits to the health of individuals and society, and thus serious consideration and scientific investigation of medical cannabis are needed.”
In the BBC documentary “Cannabis: The Evil Weed?”, Dr. John Marsden cites a UN report that says almost one in 20 adults across the globe uses cannabis each year. He goes on to discuss the history of the plant and its current status in the scientific community.
According to Marsden, the story of the cannabis plant began 50 million years ago in central Asia, most probably Kazakhstan. Cannabis is a close relative of the hop plant, but with one crucial difference. It contains the psychoactive compound THC (tetrahydrocannabinol). Why did hops evolve into cannabis? Studies have shown that THC provides resistance to ultra-violet light (which can be dangerous to plants at high altitudes) and causes a bitter taste in the leaves of the plant (to discourage animals from eating it). After it evolved, cannabis was discovered by humans and distributed from central Asia through the Tian Shan mountain chain, which stretches 2,500 km into China and Pakistan.
Along with all other forms of life, we humans evolved with cannabinoid receptors in our nervous systems, so it was only a matter of time until “plant” (cannabis) connected with “animal” (us). There is evidence of humans consuming cannabis in central Asia for nearly 3,000 years, where it was sold along the silk road with other basic commodities like salt and tea. In 2700 BC, cannabis was used in China as a treatment for pain, malaria and constipation.
Today, for the first time, scientists are trying to shed light on the density and location of cannabinoid receptors in the human brain. According to Raphael Mechoulam, Professor of Medicinal Chemistry at the Hebrew University in Jerusalem, the function of endo-cannabinoids is to act like a dimmer switch for other neurotransmitters, like dopamine. Too much of any one signal can be toxic to brain cells. For example, in the case of epilepsy, too much neurotransmitter is released, basically flooding the brain and activating too may nerve cells. However, when the cannabinoid receptors are activated, they cause the nerve cells to reduce the number of neurotransmitters that they release.
In this sense, the cannabinoid system actually protects the brain, by regulating the other neurotransmitters within it. “Cannabinoids are among the densest receptors in the brain, which is why humans are so sensitive to the psychoactive effects of THC,” explained Prof. Mechoulam.
Most cannabinoid receptors are found in the brain, where they are involved in neurological activities. Those found on the peripheral sites help regulate local tissue function. Image courtesy of Creative Commons (http://creativecommons.org/licenses/by/4.0/).
In 1996, California introduced the Compassionate Use Act, which grants those with a medical problem the ability to buy cannabis in designated stores. However, there is still confusion among CA residents because although cannabis is approved under state law, it is illegal under US federal law. Other plant-based drugs with medical uses – like aspirin – have long been exploited for their full benefits. But, for some reason, cannabis lags behind.
Only now is cannabis being considered a viable form of medicine. To create medical cannabis, developers should clone each and every plant so that the exact properties are known and consistent. After the plants are dried, they are ground down into tiny particles which are then spun and heated. The final product is a liquid which patients can spray into their mouths, or an oil which they can place under their tongues, eliminating the need for potentially harmful smoking. Some innovative new companies are focusing on bringing to the market cannabis formulations much more similar to traditional pharmaceutical formats – such as pills, gel caps, suppositories and transdermal patches.
Despite this meticulous processing, medical cannabis is still not widely available. But today, there is the possibility of treating many more ailments thanks to an unexpected property of the plant: another chemical called CBD (Cannabidiol). CBD is a non-psychoactive cannabinoid which has tremendous potential as an anti-inflammatory and also, ironically, as an anti-psychotic.
The cannabis plant cannot produce high levels of both THC and CBD. For example, recreational strains of cannabis have high concentrations of THC and almost no CBD. The challenge for developers of medical cannabis is to get the proportions right for different conditions. For example, to treat pain, you’d want a relatively equal balance of THC and CBD, because each has its own type of pharmacology, separate mechanisms of action and helpful interactive effects. But to treat inflammatory bowel diseases (IBD), such as Crohn’s and Ulcerative Colitis, or nervous system disorders, such as epilepsy and Parkinson’s Disease, you would probably want decreased levels of THC and increased levels of CBD, along with the other plant components. These “other plant components” number in the hundreds and scientists are just beginning to isolate and understand them. Another piece of the medical cannabis puzzle is creating the optimal mix of these compounds – together with THC and CBD – for different treatments.
For a plant that has been around for thousands of years, it’s surprising that new properties and uses are only now being discovered – and that the medicinal use of the plant is still so far from being widely accepted.
An April 2017 Quinnipiac University poll showed that 94% of Americans support “allowing adults to legally use marijuana for medical purposes, if their doctors prescribe it.” Towards this end, the medical community must be supplied with valid scientific proof of the efficacy of medical cannabis as a pain reliever and anti-inflammatory.