Cannabis & Neurodegenerative Diseases
(Note: I published a shortened version of this article on Leafly.)
Throughout the industrialized world, the population of those 65 years or older has been growing at shockingly faster rates than the general populations. And, given the fact age appears to the one consistent risk factor across neurodegenerative diseases, as more baby-boomers hit 65, we’re on a path to see a massive increase in new cases.
The Harvard Neurodiscovery Center put forth a chilling observation:
If left unchecked, 30 years from now, more than 12 million Americans will suffer from neurodegenerative diseases.” For patients and their families, these incurable, debilitating diseases can be devastating.
From a financial perspective, consider this shocking statistic:
In 2010, the global cost of Alzheimer’s disease was $604 billion, or 1% of global GDP.
That’s a staggering number! And, we can ignore it at our peril.
But first off, what exactly is “neurodegenerative disease?”
Neurodegenerative Disease, Defined
“Neurodegenerative disease” refers to a variety of conditions that affect neurons — or nerve cells — in the brain. Neurons comprise the building blocks of our nervous system including our spinal cord and brain.
While most people associate neurodegenerative disorders with diseases such as Multiple sclerosis (MS), Alzheimer’s or Parkinson disease, there are actually hundreds of different neurodegenerative diseases.
Most Common Forms of Neurodegenerative Disease
- Amyotrophic Lateral Sclerosis (ALS, or “Lou Gehrig’s Disease’)
- Multiple sclerosis (MS)
- Prion disease
- Spinal muscular atrophy, and others
Remarkably, Alzheimer’s is the leading cause of dementia, accounting for possibly 60-80% of cases.
What are the symptoms of neurodegenerative disease?
Symptoms, which can be severe and can sometimes cause death, vary across the spectrum, but may include:
- Cognition and memory impairment
- Problems with movement
- Spasticity (tight muscles or exaggerated reflexes)
- Rigidity or tight muscles
- Breathing problems
- Impairment of heart function
What are the causes neurodegenerative disease?
Many researchers believe a combination of factors may contribute to an increased risk of acquiring a neurodegenerative disease including genetics and environmental factors.
The one consistent risk factor of developing a neurodegenerative disorder, particularly for Alzheimer’s or Parkinson’s disease, is age.
Cannabis and the Treatment of Neurodegenerative Disease
Because cannabinoids have neuroprotective and anti-inflammatory qualities, many speculate that cannabis could prove useful in preventing, halting or reversing debilitating neurodegenerative disorder.
Juan Sanchez-Ramos, MD, PhD, a professor of molecular pharmacology and physiology at the University of South Florida, is optimistic, noting that “early laboratory studies have identified cannabinoids which by virtue of their neuro-protective and anti-oxidative actions, have the potential to slow the onset and progression of neurodegenerative conditions.”
However, Sanchez-Ramos cautions we need far more human trials, but the federal government’s long-standing position on cannabis as an illegal Schedule I drug with no known medical use, has impeded progress of researchers who face unnecessary obstacles to conduct research, a point he argued in a Tampa Bay Times Op-Ed. The government’s position has “hampered clinical research on cannabis for nearly half a century.”
What does the research on cannabis and neurodegenerative diseases say so far?
No conclusion. Not enough data.
Translation: there weren’t any good studies.
Fortunately, since publication, shifting public opinion and the legalization of medical marijuana in more than half the country, has encouraged a resurgence of research despite many of the hurdles that continue to exist.
Below, are key findings from several reviews in which the authors review a body of evidence from various studies while weeding out poorly conducted studies:
August 2015: The American Academy of Neurology published an evidence-based systematic review of randomized controlled trials using cannabis or cannabinoids to treat neurologic disorders.
They found several cannabinoids demonstrated “effectiveness” or “probable effectiveness” to alleviate spasticity, painful spasms and central pain commonly associated with multiple sclerosis. They went so far as stating medical insurance should pay for cannabinoid-derived medications such as dronabinol and nabilone for patients who could benefit.
While the Academy didn’t express opposition to insurance companies paying for herbal medical marijuana, they acknowledged their review would not likely persuade companies to cover medical marijuana because of its continued illegality by the federal government. They also suggested that currently available cannabinoid treatments may have a role in treating other neurologic conditions, but more high-quality scientific evidence was necessary before they could make a recommendation.
March 2014: The British Journal of Pharmacology published a review:
Researchers concluded that “modulating the endogenous cannabinoid system is emerging as a potentially viable option in the treatment of neurodegeneration.”
June 2012: Dr. Andras Bilkei-Gorzo published a research review:
Dr. Andras Bilkei-Gorzo noted that which to most appears to be paradoxical: cannabis, which we think of as an impairment to cognitive function, could be the exact opposite of conventional wisdom:
At first sight, it is striking that cannabinoid agonists, substances known to impair cognitive functions, could be beneficial in neurodegenerative cognitive disorders.
However, [we found] cannabinoid receptor activation could reduce oxidative stress and excitotoxicity, suppress neuroinflammatory processes and thus alleviate the symptoms of neurodegenerative motor and cognitive diseases.”
Make Cannabis Research a Top Priority
Could cannabis play a role in helping solve what could become a major public health crisis? The research so far is promising. But, clearly we still need far more. And, as a society we need to make research a top priority — it’s the compassionate and fiscally responsible thing to do.
Inevitably, the DEA will remove barriers to conducting the type of rigorous research scientists want (and need) to do. And, soon we should have better answers to some important questions:
- Can cannabis or specific cannabinoids boost the endocannabinoid system (ECS) enough to slow down, halt or reverse the progression of any of the neurodegenerative diseases?
- Can the neuroprotective or anti-inflammatory effects of cannabis or specific cannabinoids prevent onset of neurodegenerative disease or significantly decrease our risk for acquiring a disease?
As anyone who has had a family member with a neurodegenerative disease knows: watching a loved one’s health deteriorate before your very eyes can be one of the most painful experiences you’ll ever experience. We can hope that we continue making advancements in understanding not just the potential role of cannabis, but of the root causes of these diseases. And, ultimately, we can actually make a serious impact in alleviating the suffering that millions of families across the world have to go through.
Cannabis Research References:
In Cannabinoids for the Treatment of Movement Disorders – Springer 2015 University of South Florida professor, Juan Sanchez-Ramos, MD, PhD a professor of molecular pharmacology and physiology reported:
- Cannabinoids are neuroprotective and mitigate neurodegeneration in several animal models.
- Research demonstrating anti-oxidant and neuroprotective effects of cannabinoids possessed led to the award of U.S. Patent 6630507 to researchers at the US National Institute of Health (NIH), which lists the use of cannabinoids found within the C. sativa plant as useful in certain neurodegenerative diseases, such as PD, Alzheimer’s disease, and dementia caused by human immunodeficiency virus.
- Cannabinoids provide neuroprotective effects through both receptor- and nonreceptor mediated mechanisms.
- Cannabinoids are effective scavengers of reactive oxygen species and enhance endogenous antioxidant systems. This property appears to be independent of CB1 and CB2 receptor modulation and restricted to certain cannabinoids, including cannabidiol (CBD), THC, cannabinol, CP55,940, and the anandamide analog, AM404.2.
- CB2 agonists exert anti-inflammatory effects by inhibiting reactive microglia and cytokine release. CB1 agonists reduce excitotoxicity by suppressing glutamatergic activity, subsequent calcium ion influx, and nitric oxide production.