What is Alzheimer’s Disease?
Before searching for an answer to the question “Can cannabis help Alzheimer’s disease?”, it is important to first understand the disease itself. Alzheimer’s Disease (AD) is a brain disorder that, most profoundly, deteriorates a person’s memory. It is progressive in nature.
Thus, while it starts affecting memory centers, mainly by way of amyloid plaques and neurofibrillary tangles in the hippocampus (your brain’s memory encoding/retrieval center), Alzheimer’s disease eventually begins to affect almost all aspects of cognitive function.
Many would argue that Alzheimer’s disease is the most debilitating and tragic diseases known to man. While other diseases could be viewed as more physically painful and tormenting, Alzheimer’s robs you of yourself, leaving nothing but a former shell.
Think about it. What are you other than your memories? When you lose your memories, you lose your “self”. This can be incredibly tragic if you consider how saddening it would be to have a parent forget your name or that you’re their son or daughter.
Alzheimer’s disease is an alarming pandemic across the world. Did you know that over 44 million people have Alzheimer’s disease or a related dementia? That’s only counting the people that have been diagnosed! The statistics suggest that there may be another 120 million people living with Alzheimer’s disease that, sadly, are not even aware of their illness.
Alzheimer’s disease is the leading cause of dementia within the elderly demographic, particularly in Hispanics. One in nine elderly Americans suffers from Alzheimer’s disease. 66% of those affected are women.
Alzheimer’s disease costs patients over $226 Billion a year in medical and hospice expenses. That doesn’t even include the global cost of the disease, which is over $605 Billion a year. To say that Alzheimer’s is a costly disease plaguing the country is an understatement.
While there is no cure for Alzheimer’s, there are drugs and treatment options which may help the cognitive and behavioral symptoms. There have also been significant breakthroughs with deep brain stimulation. However, these current methods are costly, largely ineffective, and invasive.
Can Cannabis Help Treat Alzheimer’s Disease?
Upon initial consideration, it wouldn’t make much sense for cannabis to help Alzheimer’s disease. One of the more negative connotations of cannabis centers on its notorious ability to cause short-term memory loss. Furthermore, heavy cannabis use has been shown to even cause shrinkage of the hippocampus! Thus, how could it be that cannabis could help with Alzheimer’s — a disease characterized by its mnemonic deficits?
Well, these side effects of cannabis are typically associated with high THC strains that are smoked recreationally. When it comes to using cannabis medically, the focus is usually on the other cannabinoids present in cannabis, particularly cannabidiol (CBD). While THC is necessary to help bring out the effects of CBD (the entourage effect), strains with lower THC content are usually the targets of medical research.
When asking the question “Can cannabis help Alzheimer’s disease?”, it’s important to note that affecting the disease at its root level, causing it to reverse or vanish, is much different that alleviating the symptoms that emerge in user’s affected by the disease.
The typical drugs prescribed for Alzheimer’s are cholinesterase inhibitors. Since choline is an important neurotransmitter in the hippocampus and esterase breaks down choline, then inhibiting that breakdown might increase hippocampal function.
That’s why, often times, people looking for a “brain boost” take cholinesterase inhibitors to improve their memory. Unfortunately for Alzheimer’s disease patients, the medication only delays symptoms for a few months until the disease inevitably progresses.
Furthermore, nausea, loss of appetite, and increased frequency of bowel movements are common side effects of these medications. Let’s see… what can you think of that helps all of those symptoms? Cannabis!
In 2012, experts in the field stated that cannabinoids show anti-inflammatory, neuroprotective and antioxidant properties, and immunosuppressive effects. (Ref. 1) All of these would help with the symptoms of Alzheimer’s. They recommended that CBD could have particularly potential since it binds to CB2 receptors and is non-psychoactive. Seeing as the psychoactive aspects of cannabis could further disorient Alzheimer’s disease patients, CBD sounded particularly promising.
However, that statement was merely speculation. In order to have a medication be approved for massive use, clinical trials must be performed. Clinical trials do their best to assure that the drug being used to help a disease is the only contributing variable to any improvements.
While some have claimed that cannabis can help treat the symptoms of Alzheimer’s itself, and not just the symptoms of the prescribed drugs, little to no clinical studies have been done to link cannabis with Alzheimer’s disease treatment. However, initial research has paved the way for forthcoming clinical trials.
For example, research in 2003 demonstrated that cannabis has great therapeutic potential in neurodegenerative disorders, including Alzheimer’s. (Ref. 2) The article also provided a great overview of the endocannabinoid system and how cleverly altering its activity could reverse Alzheimer’s disease.
In 2006, another study showed that THC inhibits the enzyme acetylcholinesterase (AChE). AChE is known for being the key pathological marker of Alzheimer’s disease. (Ref. 3) Furthermore, the study found that THC binds to AChE better than currently approved drugs prescribed for the treatment of Alzheimer’s disease.
This research suggests that THC “may directly impact the progression of this debilitating disease”. Another study points out that cannabis has been shown to reduce oxidative stress, neuroinflammation, and the formation of amyloid plaques and neurofibrillary tangles. All of these are symptoms of late-onset Alzheimer’s disease. (Ref. 4) Furthermore, studies have shown that cannabinoids can reduce dementia-related symptoms.
A study in 2007 also corroborates this claim. (Ref. 5) Furthermore, synthetic THC, branded as Dronabinol, has been shown to be effective. (Ref. 6). This is surprising since the “Entourage Effect” usually mandates the presence of all cannabinoids in order for THC to be effective. Synthetic THC showing efficacy is huge news, since that means it can be processed and distributed with ease!
A review article in 2014 unveiled that activation of CB1 and CB2 receptors by natural or synthetic means has beneficial effects in Alzheimer’s disease, even at lower, non-psychoactive doses. (Ref. 7) The study points out that such results should encourage clinical trials on a massive scale.
Furthermore, a study showed that CB1 receptor deficiency in mice led to cognitive impairment that resembled that in patients with Alzheimer’s disease. (Ref. 8) This research suggests that activation of CB1 receptors by way of ingesting cannabis could help with cognitive impairment experienced by Alzheimer’s patients.
CB2 receptor deficiency also seems to play a role in Alzheimer’s Disease as well. In a rodent study, treatment with cannabis yielded positive cognitive effects in mice that had deficient CB2 receptors. (Ref. 9)
While further research must be done, perhaps activation of the CB1 and CB2 receptors through THC can serve as the primary mechanism of action for the alleviation of Alzheimer’s Disease symptoms. However, it does not directly address if the disease will be reversed. However, it’s progression could be significantly curtailed by counteracting the CB1 and CB2 deficits caused by Alzheimer’s Disease.
It’s unfortunate that the research available is currently so limited. This is most likely due to the negative connotation associated with marijuana from mainstream media over the past several decades. Even though a majority of the studies cited in this article emphasized exercising caution in using cannabis as a treatment method because of its psychoactive effects, studies have shown that cannabinoids may be effective at doses lower than psychoactive onset.
Furthermore, CBD shows great promise; it is not psychoactive at all. However, in an unexpected twist, THC actually seems to be the most effective cannabinoid for helping with, at least, the symptoms of Alzheimer’s disease. A recent study published in February 2016 found that medical cannabis oil is a safe and viable treatment option for Alzheimer’s patients. (Ref. 10) Perhaps this study marks the initial foray into bringing cannabis into the mainstream as a viable treatment option for Alzheimer’s disease.
In an ideal world, clinicians would perform massive clinical trials on cannabis to see how it compares to current treatment options. While the studies mentioned above suggest that THC binds more effectively that current options to the enzyme that causes many of the problems of Alzheimer’s disease, doctors and professionals seem to look past cannabis as an effective treatment option.
Perhaps this will change in the future. If you or a loved one has Alzheimer’s Disease and is struggling with finding a proper treatment option, consult with a doctor to see if cannabis is a viable treatment option.
References for “Can Cannabis Help Alzheimer’s Disease?”
(1) T Karl, et al., The therapeutic potential of the endocannabinoid system for Alzheimer’s disease, Expert Opinion on Therapeutic Targets, Volume 16, Issue 4, 2012. http://www.tandfonline.com/doi/abs/10.1517/14728222.2012.671812?journalCode=iett20
(2) D Baker, et al., The theraputic potential of cannabis, The Lancet Neurology, Volume 2, Issue 5, May 2003, Pages 291–298. http://www.sciencedirect.com/science/article/pii/S1474442203003818
(3) L Eubanks, et al., A Molecular Link between the Active Component of Marijuana and Alzheimer’s Disease Pathology, Mol. Pharm. , 2006, 3 (6), pp 773–777. http://pubs.acs.org/doi/abs/10.1021/mp060066m
(4) A Ahmed, et al., Cannabinoids in late-onset Alzheimer’s disease, Clinical Pharmacology & Therapeutics, Cannabinoids, Volume 97, Issue 6, pages 597–606, June 2015. http://onlinelibrary.wiley.com/doi/10.1002/cpt.117/abstract
(5) V Campbell and A Gowran, Alzheimer’s disease; taking the edge off with cannabinoids?, British Journal of Pharmacology, Special Issue: Cannabinoid Pharmacology, Volume 152, Issue 5, pages 655–662, November 2007. http://onlinelibrary.wiley.com/doi/10.1038/sj.bjp.0707446/full
(6) M Woodward, et al., Dronabinol for the Treatment of Agitation and Aggressive Behavior in Acutely Hospitalized Severely Demented Patients with Noncognitive Behavioral Symptoms, The American Journal of Geriatric Psychiatry Volume 22, Issue 4, April 2014, Pages 415–419. http://linkinghub.elsevier.com/retrieve/pii/S1064748112000942
(7) E Aso and I Ferrer, Cannabinoids for treatment of Alzheimer’s disease: moving toward the clinic, Front. Pharmacol., 05 March 2014. http://journal.frontiersin.org/article/10.3389/fphar.2014.00037/abstract
(8) C Stumm, et al., Cannabinoid receptor 1 deficiency in a mouse model of Alzheimer’s disease leads to enhanced cognitive impairment despite of a reduction in amyloid deposition, Neurobiology of Aging, Nov 2013, Volume 34, Issue 11, pages 2574-2584. http://www.neurobiologyofaging.org/article/S0197-4580(13)00240-6/abstract
(9) A Ester, et al., Cannabinoid Receptor 2 Participates in Amyloid-β Processing in a Mouse Model of Alzheimer’s Disease but Plays a Minor Role in the Therapeutic Properties of a Cannabis-Based Medicine, Journal of Alzheimer’s Disease, vol. Preprint, no. Preprint, pp. 1-12, 2016. http://content.iospress.com/articles/journal-of-alzheimers-disease/jad150913
(10) S Assaf, et al., Safety and Efficacy of Medical Cannabis Oil for Behavioral and Psychological Symptoms of Dementia: An-Open Label, Add-On, Pilot Study, Journal of Alzheimer’s Disease, vol. 51, no. 1, pp. 15-19, 2016. http://content.iospress.com/articles/journal-of-alzheimers-disease/jad150915