Dr. David Bearman, Contributor
Identifying the biggest lie told about cannabis is similar to trying to name Donald Trump’s most outrageous statement; it’s impossible. But by far, one of the most pervasive lies about cannabis is that it kills brain cells, and few things could be more wrong.
There are more than 5.3 million people in the U.S. living with disabilities related to traumatic brain injury (TBI). Every year, there are nearly 56,000 deaths and approximately 80,000 cases of severe disability related to traumatic brain injuries in the United States. Because cannabis and cannabinoids are neuroprotective, their use could decrease the incidence of both TBI and stroke from traumatic brain injury. That is because cannabinoids can prevent neuronal cell death.
That bears repeating; cannabinoids prevent neuronal cell death.
This is important both because there is no effective pharmaceutical drug (except for maybe Marinol) that treats traumatic brain injury to decrease the size of the damage caused by stroke or TBI. If it is administered within three hours of a TBI, tPA can dissolve blood clots involved in stroke. Having cannabis on board can limit damage from blood loss, but there still may be brain damage.
The leading research laboratory in the world on the effects of cannabis and cannabinoids on the brain and the endocannabinoid system is that of Dr. Raphael Mechoulam at Hebrew University in Israel. According to Dr. Esther Shohami, a colleague of Mechoulam’s, “The secondary effects of brain injuries, such as swelling and the release of toxic chemicals, can be more damaging than the initial blow.” A synthetic, dexabinol, has been shown to treat neuro inflammatory disorder. Dexabinol was developed by Dr. Mechoulam.
Glutamate, stress and the calcium that causes the damage
It turns out that during an ischemic episode (decreased blood flow), large quantities of the excitatory neurotransmitter glutamate are released. This event causes neuronal death by over-stimulating two or three different receptors, and results in both metabolic stress and accumulation of toxic levels of intracellular calcium. Studies have shown that glutamate toxicity may be prevented by antioxidants. Cananbidiol (CBD), THC, and several synthetic cannabinoids have been demonstrated to be antioxidants.
Glutamate toxicity can be reduced by antioxidants
Cannabis and cannabinoids like CBD have been shown to limit the damage caused by ischemic brain injury. THC and its psychoactive analogues also have been reported to be neuroprotective against in vitro glutamate toxicity.
Cannabinoids have been suggested to prevent glutamate neurotoxicity by activating cannabinoid receptors, which can reduce calcium influx through voltage sensitive calcium channels.
How Cannabinoids Work to Protect the Brain
There are two types of cannabinoids; those sourced from the cannabis plant (the phytocannabinoids) and those made by the human body (the endogenous cannabinoids). Both work on the endocannabinoid system, a neural network found on the central and peripheral nervous system that regulate essential human functions like pain, mood, digestion, sleep and appetite.
The endogenous cananbinoid 2-AG is believed to work in four ways; it reduces the level of glutamate, decreases free radicals, decreases TNF and increases blood flow to the brain. All four mechanisms contribute to limiting the cellular damage done after the primary insult to the brain.
The neuroprotective actions of CBD and other cannabinoids were studied in rat cortical neuron culture. Rat cortical neuron cultures were exposed to toxic levels of glutamate. The excitatory neurotransmitter overproduction of glutamate becomes excitotoxic and kills neurons. CBD and THC found in cannabis block this overproduction so that glutamate toxicity is reduced.
So, as most Americans have been taught, rather than killing brain cells cannabis has actually been shown to limit the damage to the brain caused by TBI. The allegation that cannabis use harms the brain is not based on science—that is, unless you will deprive monkeys of oxygen by putting gas masks on them and replacing the oxygen with smoke. In the case of that “research” we know depriving the brain of oxygen actually causes brain damage. Not cannabis.
It is time to tell the politicians to stick to politics and stay out of science and out of the way of research. Cannabis has shown itself to be an alternative to opiates, to treat ADD, ADHD, all Autism Spectrum Disorder, autoimmune disorders and even ameliorate some of the symptoms of PTSD. We have also known, since 1974, that cannabis kills cancer cells.
