How CBD Helps with Alzheimer’s Disease
The suggested neuroprotective, anti-inflammatory, and antioxidant properties of cannabidiol (CBD), the non-psychoactive hemp derivative, have been explored and studied for their prospective benefits for Alzheimer’s disease(1).
Alzheimer’s disease (AD) is the most common form of dementia that involves progressive and irreversible damage in memory and cognitive skills(2).
The degenerative cause of Alzheimer’s disease is believed to start in the hippocampus region of the brain that is responsible for memory(3).
Some of the characteristics of the brain of a patient with Alzheimer’s disease include the following(4):
- Presence of beta-amyloid protein build-up (amyloid plaques)
- Abnormal accumulation of tau protein (neurofibrillary tangles)
- Chronic inflammation
- Hardening of the arteries (atherosclerosis)
- Beta-amyloid accumulation in the brain arteries
This disease disrupts neurons, resulting in apoptosis (cell death) and loss of neuron function(5).
According to a clinical and scientific review of Alzheimer’s, the disease usually occurs in females over 65(6). The symptoms of Alzheimer’s comes in three stages: the early stage, middle stage, and late-stage(7).
People with Alzheimer’s may exhibit the following symptoms depending on the severity of the disease(8):
- Memory loss
- Mood and personality changes
- Increased anxiety or aggression
- Inability to learn new things
- Problem recognizing family and friends
- Hallucinations, paranoia, and delusions
- Inability to communicate
- Increase sleeping
- Loss of bladder and bowel control
It was reported in a study that endocannabinoids, particularly CBD, may play a vital role in the management of Alzheimer’s disease by offsetting the hyperactivity of amyloid-induced tau protein’s inflammatory and neurochemical consequences(9).
These amyloid-induced tau proteins may accumulate or form an abnormal aggregate that is said to cause Alzheimer’s(10). Endocannabinoids are naturally occurring compounds that may be found in Cannabis sativa.
Another research on the potential functionality and role of the endocannabinoid system (ECS) in the treatment of Alzheimer’s disease reported that cannabinoids showed immunosuppressive effects and neuroprotective, anti-inflammatory, and antioxidant properties(11).
The ECS is responsible for the different inflammatory and immune activities and other central nervous system functions(12).
This neuromodulatory system has two primary receptors: the CB1 receptor, which regulates memory, motor control, and mood, and the CB2 receptor that is accountable for immunomodulatory functions(13).
The psychological deficiencies of Alzheimer’s patients may be linked to the cerebral disturbances in the hippocampus and frontal cortex part of the brain that are known to be abundant in CB1 receptors(14).
It was also noted that CB2 receptors in patients with Alzheimer’s were correlated with beta-amyloid plaques and levels(15).
This receptor demonstrated the potential to assist in beta-amyloid processing and may prevent neuroinflammation in people with Alzheimer’s disease(16).
Tetrahydrocannabinol (THC), the compound found in cannabis that has psychoactive effects, is shown to have a high affinity with the CB1 receptor(17).
Although CBD alone binds weakly with CB1 and CB2 receptors, it was reported in a study that CBD is said to have the capability to antagonize these receptors in the presence of THC(18).
A study also noted the neurogenesis and neuroinflammatory influences of the ECS on Alzheimer’s disease(19).
It was reported that CBD has the potential to promote neurogenesis and lessen the production of the compressed fibrous neuroglia network (gliosis)(20).
However, these promising benefits of cannabinoids in the pharmacology of Alzheimer’s disease requires further clinical trials.
Benefits of Using CBD Oil for Alzheimer’s Disease
CBD is known to have beneficial effects in psychiatric diseases, like depression, anxiety, and psychosis(21).
A murine model of cerebral malaria showed that adjunct therapy using CBD improved the test subjects’ behavioral and cognitive functions(22).
Several studies reported CBD’s possible neuroprotective, anti-inflammatory, and antioxidant properties(23). The research discussed how CBD may help in the supplemental remedy of people who suffer from neurological disorders.
In in vitro (test tube experiment done in the laboratory) models of Alzheimer’s disease, researchers examined CBD’s protective role in synaptic plasticity. This ability is defined as the changes in synapses (junctions between neurons), enabling neurons to communicate.
It was noted that CBD had protective properties against beta-amyloid peptide’s neurotoxic effects, resulting in neurodegeneration(24).
A study suggested that several cannabinoids showed possible neuroprotective effects by acting on the CB1 and CB2 receptors of the ECS(25).
The neuroprotective properties of CBD were further investigated in a study showing how the treatment of cells with CBD greatly enhanced cell survival. The paper showed that CBD averted beta-amyloid-induced neurotoxicity.
Neuroprotective means the ability to protect brain cells and nerves from impairment and possible death(26).
An animal study showed that CBD demonstrated neuroprotective activities in hypoxia-ischemia (HI)-induced (temporary occlusion of hypoxia and carotid arteries) newborn piglets(27).
It was noted in the study that CBD had exhibited little to no adverse effects when administered.
Preclinical research on neurodegenerative disorders focused on the neuroprotective properties of CBD along with its antioxidant and anti-inflammatory effects(28).
The researchers observed that CBD had anti-inflammatory properties beneficial for neuroinflammatory diseases, like multiple sclerosis(29).
CBD’s anti-inflammatory effects were also associated with microglial cell migration, including the production of pro-inflammatory mediators targeting CB2 receptors(30).
Individuals with Alzheimer’s disease exhibited high oxidative stress and damage connected with amyloid plaques and neurofibrillary tangles(31).
A study mentioned that the antioxidant and anti-inflammatory properties of CBD had the potential to protect against oxidative stress and its resulting protein and lipid modification(32).
Another study suggested that the combined use of CBD and THC demonstrated neuroprotective effects in animal models of Parkinson’s disease because of their antioxidant properties(33).
CBD and Neurological Disorders
Alzheimer’s disease is said to comprise 60 to 70% of dementia cases(34).
This condition is followed by other types of dementia, like vascular dementia (caused by impaired blood flow in the brain), Lewy bodies dementia (abnormal protein development in nerve cells), and frontotemporal dementia (deterioration of the brain’s frontal lobe).
The symptoms of dementia are similar to the symptoms of Alzheimer’s. Dementia also starts with memory loss or forgetfulness, behavior changes, and increasing difficulty in communication and walking(35).
According to a study, conventional medications for treating Alzheimer’s disease offer limited therapeutic effects and are associated with adverse effects(36).
Animal studies noted CBD’s effectiveness in treating acute seizures in mice and rat models(37). Seizures are one of the prominent symptoms of Alzheimer’s.
Findings may support CBD’s promise as a potential alternative in helping patients manage Alzheimer’s disease symptoms. However, these studies are limited and inconclusive.
Other studies examined CBD’s beneficial effects on other neurological diseases. These conditions include Parkinson’s disease, a brain disorder that results in balance and coordination difficulties, stiffness, and shaking, and Huntington’s disease, a progressive brain impairment that causes changes in the central nervous area.
Similar to Alzheimer’s, both of these diseases cause memory loss and cognitive disabilities.
Eight patients with Parkinson’s disease were administered CBD as a supplement to their usual therapy. Results showed that the rating scale in the psychosis questionnaire has significantly decreased(38).
However, a controlled clinical trial of CBD for Huntington’s disease suggested that the administration of 700mg of CBD a day for six weeks did not show any beneficial or adverse effects to patients with the disease(39).
How Soon Can CBD Oil be felt?
CBD oil, which is extracted from hemp, may be in the form of a tincture, vape pen cartridges, topicals, edibles, and patches(40).
It is common practice to take CBD oil tinctures sublingually(41). However, they may also be infused in edibles, like capsules and gummies, or applied topically.
Different forms of CBD oil also have various onset times. These types of CBD may be categorized by delivery systems or according to the routes in which they are taken(42).
CBD administration routes include inhalation, sublingual absorption, ingestion, and transdermal and topical application(43).
Sublingual delivery is when the CBD oil is dispensed under the tongue through a dropper and held for at least 90 seconds for the mouth’s mucous membrane to absorb the product(44).
Through this method, CBD avoids passing through the stomach and liver and is diffused in the capillaries, eventually penetrating the bloodstream.
Taken sublingually, CBD’s bioavailability or absorption rate is at 6% to 20%. These figures are higher than the bioavailability of ingested CBD products(45).
Moreover, CBD sublingual absorption has a 15 to 30-minute onset time. Its effects may last from 4 to 6 hours.
Ingestion of CBD is the most common method of administering CBD oil(46). This approach is also known as the “first-pass effect.”
In this route of delivery, CBD passes through the liver before being absorbed into the bloodstream.
Onset time ranges from 30 to 90 minutes, depending on your body’s metabolism. This period is relatively long compared to the onset time of other routes of administration(47). However, the duration of the effects of CBD ingestion lasts the longest: 6 to 8 hours at most.
Edibles, including capsules, gummies, drinks, candies, and others, are the standard CBD products that may be administered through ingestion.
The delivery method that has the fastest onset time is the inhalation method through vaping and smoking(48).
Inhalation has an onset time of 2 to 15 minutes before the user experiences CBD’s effects. This method allows CBD to be absorbed through the lungs and into the bloodstream.
Vaping or smoking has an absorption rate of 17% to 44%, and its effects may last for 2 to 4 hours(49). However, according to the National Institute on Drug Abuse, some case studies reported that smoking marijuana may increase susceptibility to lung infections(50).
CBD gels and patches use the transdermal absorption route. This method allows CBD to penetrate the dermis of the skin and go into the bloodstream(51).
Transdermal CBD products have an onset time of 15 to 30 minutes and may last for 4 hours for gels and 8 hours for transdermal patches. Transdermal patches are CBD-infused adhesive products that are normally applied to the wrist or ankle(52).
Topical CBD products may be applied directly to the skin for more targeted relief(53). These topicals are generally used to reduce skin inflammation, itchiness, or muscle pain.
This method does not pass through the bloodstream. Instead, it allows CBD to interact with the CB2 receptors of the skin(54).
A 10 to 15 minutes onset time is expected when using CBD topicals. Its effects may last from 2 to 4 hours.
Risks of Using CBD for Alzheimer’s
A review on the safety and side effects of CBD reported that CBD generally has a safe and better side effect profile compared to other drugs(55).However, treating Alzheimer’s with CBD needs to be handled with caution to avoid adverse effects and further damage to the quality of life of the patient.
Aside from CBD’s benefits, there are also known side effects that need to be considered before administering CBD to individuals with Alzheimer’s.
Some of the common adverse effects of CBD include(56):
- Dry mouth
- Changes in appetite
- Changes in weight
Other risks of CBD include its possible drug-to-drug interactions. CBD may reduce or increase another drug’s effect(57).
CBD may induce sleepiness and drowsiness(58). Medications with similar effects should be taken with caution.
CBD and Its Legality
Industrial hemp is the derivative of Cannabis sativa with a low amount of THC and more abundant quantities of CBD. Under the 2018 Farm Bill, it is federally legal to manufacture CBD-rich hemp products in the United States(59).
However, the US Food and Drug Administration (US FDA) approved one CBD-infused drug for the treatment of childhood epilepsy only: Epidiolex. The medication aims to help treat rare forms of epilepsy, like Lennox-Gastaut syndrome and Dravet syndrome(60).
There is no universally accepted and approved CBD dosage for wellness or possible treatment of a condition. You should consult a doctor to avoid overdose or unwanted drug-to-drug adverse effects.
For first–time users, it is advisable to start low and go slow when it comes to CBD. Starting with a low dosage of CBD may allow users to adjust their dose more efficiently and carefully.
Things to Consider When Buying CBD Products for Alzheimer’s
Although CBD has promising benefits in managing Alzheimer’s disease symptoms, you must evaluate the following before picking the best CBD oil product for this disorder.
Type of CBD Extract
CBD and THC are found in the Cannabis plant. Their significant difference lies in their ability to induce euphoria.
CBD is the non-addictive and non-psychoactive cannabinoid normally found in hemp or cannabis strains that contain 0.3% THC. Contrastingly, THC is the psychoactive component of marijuana that has the ability to produce a high in users(61).
CBD products are categorized into three types based on the content of the extract. Broad-spectrum CBD and CBD isolates do not have any traces of THC.
Moreover, broad-spectrum CBD has some cannabinoids present in the hemp plant (except THC), while CBD isolates have pure CBD only(62).
Meanwhile, the whole-plant extract or full-spectrum CBD contains all the phytocannabinoids found in the hemp plant, including traces of THC, terpene profiles, and flavonoids. These phytocompounds and cannabinoids are believed to produce a synergistic effect known as the entourage effect(63).
Source of Hemp
Knowing the source of hemp oil or CBD extract used in a product, the quality of hemp, farming methods used, and the company’s protocols and regulations help when picking the right CBD product.
Most CBD brands claim that they use organic, US-grown hemp. Oregon, Colorado, North Carolina, and Kentucky are a few states that are part of the hemp pilot program(64).
These states follow the US Department of Agriculture’s (USDA) procedures in researching and cultivating industrial hemp(65).
Certificate of Analysis
It is a prudent choice to examine the certification of analysis (COA) of each CBD product before deciding to buy it.
The COA shows the information on the CBD concentration and potency of the product and the laboratory results for microbials, chemicals, solvents, and pesticides.
Laboratory tests may be conducted by the brand (an in-house lab test) or by a third-party laboratory.
Amount of CBD Concentration and Potency
The CBD concentration and potency indicated in the COA features the amount of CBD per container and the amount of CBD per serving. These details may be useful when deciding on the dosing and administration of CBD products.
The CBD extraction method is the process in which the hemp extract is obtained. It determines the purity and quality of the CBD extract.
Ethanol and CO2 extraction methods are the most commonly used approaches in obtaining CBD extracts(66).
It is best to check the CBD product’s ingredients to be aware of the possible allergic reactions you may have to its components. This practice also avoids the occurrence of adverse effects upon CBD intake.
CBD products often contain carrier oils that may contribute to the beneficial effects of CBD. Two of the most common carrier oils are medium-chain triglyceride (MCT) coconut oil and hempseed oil.
Hempseed oil is known for being a source of healthy digestible proteins and dietary nutrients(67). Moreover, MCT oil is commonly derived from coconuts and has omega-3 suitable for cardiovascular diseases(68).