What does science say about the relationship between cannabinoids and Alzheimer's?

Studies suggest that the major cannabinoids found in hemp reduce plaque and tangle build-up, and therefore show viable potential as complementary treatment options for Alzheimer's disease. The possible efficacy of cannabis for Alzheimer's disease has been linked to its interaction with the endocannabinoid system, which modulates various pathological processes associated with neurodegenerative disorders, including neuroinflammation, excitotoxicity, mitochondrial dysfunction, and oxidative stress. CB1 receptors of the endocannabinoid system have been shown to regulate neurotransmitters involved in excitotoxic neurodegenerative processes, while CB2 receptors have been shown to reduce inflammation associated with Alzheimer's disease.

The use of cannabinoids has been shown to be effective in reducing beta-amyloid levels and improving mitochondrial function, leading the researchers to conclude that "complementary therapy with cannabinoids could be a potential therapeutic option for Alzheimer's through multiple functions and pathways. " A previous study also found that various cannabinoid compounds are effective in preventing beta amyloid aggregation, indicating that it could affect disease progression. Another study showed that cannabinoid therapy can reduce night motor activity and agitation in patients with dementia, suggesting that it may be also beneficial in treating behavioral and circadian disorders.

Lack of glucose uptake has been linked to a worsening of brain diseases such as Alzheimer's disease, and findings in an animal trial suggest that prolonged use of cannabionoids may promote increased glucose uptake in the brain, and that hemp-derived cannabinoid compounds could be beneficial in treating Alzheimer's disease through multiple methods.

Cannabinoids provide a multifaceted approach to the treatment of Alzheimer's that undoubtedly must be thoroughly studied to find its true use, but today the horizon is full of high hopes.

Sources:

1. Alzheimer’s disease. (2014, June 17). Mayo Clinic. Retrieved from http://www.mayoclinic.org/diseases-conditions/alzheimers-disease/basics/definition/con-20023871.
2. Amanullah, S., MacDougall, K., Sweeney, N., Coffin, J., and Cole, J. (2013). Synthetic cannabinoids in dementia with agitation: Case studies and literature review. Clinical Neuropsychiatry, 10 (3-4), 142-147. Retrieved from https://pdfs.semanticscholar.org/b8be/e18d22e95dbe90cf6057e9f4648d9b3c5b02.pdf?_ga=1.196675940.916023079.1489098264.
3. Bedse, G., Romano, A., Lavecchia, A.M., Cassano, T., and Gaetani, S. (2015). The role of the endocannabinoid signaling in the molecular mechanisms of neurodegeneration in Alzheimer’s disease. Journal of Alzheimer’s Disease, 43(4), 1115-36. Retrieved from http://content.iospress.com/articles/journal-of-alzheimers-disease/jad141635.
4. Cao, C., Li, Y., Liu, H., Bai, G., Mayl, J., Lin, X., Sutherland, K., Nabar, N., and Cai, J. (2014). The potential therapeutic effects of THC on Alzheimer’s disease. Journal of Alzheimer’s Disease, 42(3), 973-84. Retrieved from http://content.iospress.com/articles/journal-of-alzheimers-disease/jad140093.
5. Currais, A., Quehenberger, O., Armando, A.M., Daugherty, D., Maher, P., and Schubert, D. (2016, June 23). Amyloid proteotoxicity initiates an inflammatory response blocked by cannabinoids. Aging and Mechanisms of Disease, doi:10.1038/npjamd.2016.12. Retrieved from http://www.nature.com/articles/npjamd201612–.
6. Eubanks, L.M., Rogers, C.J., Beuscher, A.E. 4th, Koob, G.F., Olson, A.J., Dickerson, T.J., and Janda, K.D. (2006, November-December). A molecular link between the active component of marijuana and Alzheimer’s disease pathology. Molecular Pharmaceuticals, 3(6), 773-7. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2562334/.
7. Garcia-Arencibia, M., Garcia, C., and Fernandez-Ruiz, J. (2009, December). Cannabinoids and Parkinson’s disease. CNS & Neurological Disorders Drug Targets, 8(6), 432-9. Retrieved from http://www.eurekaselect.com/93569/article.
8. Köfalvi, A., Lemos, C., Martin-Moreno, A.M., Pinheiro, B.S., García-García, L, Poso, M.A., Valerio-Fernandes, A., Beleza, R.O., Agostinho, P., Rodrigues, R.J., Pasquare, S.J., Cunha, R.A., and de Ceballos, M. (2016, March 11). Stimulation of brain glucose uptake by cannabinoid CB2 receptors and its therapeutic potential in Alzheimer’s disease. Neuropharmacology, doi:10.1016/j.neuropharm.2016.03.015. Retrieved from http://www.sciencedirect.com/science/article/pii/S0028390816300879.
9. Krishnan, S., Cairns, R., and Howard, R. (2009, April 15). Cannabinoids for the treatment of dementia. Cochrane Library, 2, 10.1002/14651858.CD007204.pub2. Retrieved from http://onlinelibrary.wiley.com/wol1/doi/10.1002/14651858.CD007204.pub2/full.
10. Liu, C.S., Chau, S.A., Ruthirakuhan, M., Lanctôt, K.L., and Herrmann, N. (2015, August). Cannabinoids for the treatment of agitation and aggression in Alzheimer’s disease. CNS Drugs, 29(8), 615-23. Retrieved from http://link.springer.com/article/10.1007%2Fs40263-015-0270-y.
11. Manuel, I., Lombardero, L., Laferla, F.M., Giménez-Llort, L., and Rodríguez-Puertas, R. (2016, August 4). Activity of muscarinic, galanin and cannabinoid receptors in the prodromal and advanced stages in the triple transgenic mice model of Alzheimer’s disease. Neuroscience, 329, 284-93. Retrieved from http://www.sciencedirect.com/science/article/pii/S0306452216301610.
12. Orr, A.L., Hanson, J.E., Li, D., Klotz, A., Wright, S., Schenk, D., Seubert, P., Madison, D. V. (2014). Amyloid-beta inhibits E-S Potentiation through suppression of cannabinoid receptor 1-dependent synaptic disinhibition. Neuron, 82(6), 1334–1345. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4114400/.
13. Ramírez, B.G., Blázquez C., Gómez del Pulgar, T., Guzmán, M., de Ceballos, M.L. (2005, February 23). Prevention of Alzheimer’s disease pathology by cannabinoids: neuroprotection mediated by blockade of microglial activation. The Journal of Neuroscience, 25(8), 1904-13. .
14. Shelef, Assaf. Barak, Y., Berger, U., Paleacu, D., Tadger, S., Plopsky, I., and Baruch, Y. (2016, February 27). 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, 51(1), 15-19. Retrieved from http://content.iospress.com/articles/journal-of-alzheimers-disease/jad150915.
15. Walther, S., Mahlberg, R., Eichmann, U., and Kunz, D. (2006, May). Delta-9-tetrahydrocannabinol for nighttime agitation in severe dementia. Psychopharmacology, 185(4), 524-8. Retrieved from http://link.springer.com/article/10.1007%2Fs00213-006-0343-1.
16. What Is Alzheimer’s? (n.d.). Alzheimer’s Association. Retrieved from http://www.alz.org/alzheimers_disease_what_is_alzheimers.asp#symptoms.