Keeping The Brain and Central Nervous System Healthy

The statements mentioned in this content have not been evaluated by the FDA, and are not intended to prevent, diagnosis, or treat any disease. Always work with your personal healthcare provider. 

 

There’s a lot of evidence building up in the medical literature to show cannabidiol and other cannabinoids like CBG protect the brain. They can do this in a number of ways, including acting as antioxidants and reducing neuroinflammation.¹ This means they’re useful in supporting the health of patients with Alzheimer’s disease, Huntington’s, Parkinson’s, autism, ADHD, epilepsy, schizophrenia, and multiple sclerosis. In this chapter, I’ll talk about how CBD and other cannabinoids can promote neurological health and keep your brain healthy and strong now and throughout your golden years. CBD and phytocannabinoids found in hemp oil may be the solution to keep your independence as you age.

 

Alzheimer’s

Alzheimer’s disease (AD) is a neurodegenerative disease that is the most common form of dementia, responsible for more than 60% of cases.² Worldwide, 33 million people suffer from this debilitating illness.² Alzheimer’s disease is characterized by cognitive decline caused by the buildup of amyloid beta (Aβ) proteins. These sticky proteins disrupt communication between brain cells and activate immune cells. The activated immune cells trigger inflammation. In turn, brain cells are destroyed. Cell culture studies have shown CBD can protect against neurotoxicity caused by Aβ.²

Inflammation that occurs in the brain and central nervous system (CNS) is called neuroinflammation. Cells in the CNS known as astrocytes keep this important bodily system balanced by recycling of neurotransmitters and providing nutrients to neurons. Any injury to the CNS can lead to changes in these astrocytes. These changes are what scientists call reactive gliosis. CBD can reduce reactive gliosis and neuroinflammation to encourage neurogenesis, the creation of new brain cells.²

In cell culture studies, CBD protects neurons, blocks the degeneration of brain cells, and controls the migration of immune cells known as microglia.² Microglial activation is toxic to the brain and CBD protects against this neurotoxicity.² In vitro, CBD also reduces tau overexpression.² Like amyloid beta, tau is a protein that accumulates in the brain. It has some beneficial effects, but it can form clumps of toxic neurofibrillary tangles, which lead to the neurodegeneration of Alzheimer’s.

In rodent models of Alzheimer’s, CBD reverses and stops cognitive dysfunction.^2,3 Other rodent models of Alzheimer’s disease have found CBD promotes a healthy inflammatory response.⁴ It’s also neuroprotective.⁴ For example, in a mouse model of AD, the scientists injected the animals with human amyloid beta and then treated the animals daily with abdominal injections of CBD for a week.⁴ CBD suppressed a marker of activated astrocytes that is one of the main features of reactive gliosis caused by the buildup of amyloid beta. The results suggested CBD reduced damage caused by Aβ. Other animal research shows CBD can block the gliosis and neuroinflammation linked to Alzheimer’s.⁵

It also promotes neurogenesis.⁵

Most impressively, researchers induced Alzheimer’s in mice by injecting the animals with Aβ. CBD injections for 1 week and then 3 times/week for the following 2 weeks improved cognition.³ The researchers measured the spatial learning of the mice by having them try to navigate the Morris Water Maze. Spatial learning refers to the ability to find your way in and around your surroundings. CBD treatment reversed the cognitive problems that occurred in the mice injected with Aβ and improved spatial learning in the animals.

In a mouse model of genetic Alzheimer’s, animals were treated for three weeks with injections of CBD after they developed cognitive problems and signs of AD pathology in their brains.⁶ CBD reversed the cognitive declines in two types of memory: object recognition and social recognition.

Unfortunately, despite a lot of evidence from preclinical animal studies showing CBD may have a role to play in supporting the health of Alzheimer’s patients, to my knowledge there haven’t been any human studies of CBD in AD. Hopefully, based on all the promising preclinical evidence, scientists will soon study CBD’s effects in this group of people.

 

Parkinson’s Disease

Parkinson’s disease (PD) is a common neurodegenerative disorder. Its prevalence increases with age, with 1% of the population over 60 years old suffering from the disorder.⁷ There are two primary characteristics of the disease. First, there’s what scientists call motor impairment which includes hypokinesia (slow movement), tremors, and muscle rigidity. Second, people with PD have non-motor symptoms such as sleep disturbances, cognitive problems, anxiety, depression, and psychotic symptoms. These problems are caused by the destruction of neurons that produce the brain chemical dopamine. This leads to low levels of dopamine, an important neurotransmitter involved in feeling pleasure, thinking, planning, and focusing.

Several human studies show CBD may have some impressive benefits in people with PD. In one of those studies, researchers investigated the effects of CBD in six PD patients who had psychotic symptoms for at least three months.⁸ The patients received a flexible oral dose of CBD starting with 150 mg/day for four weeks combined with their standard therapy. After using CBD, the participants experienced a significant improvement in the Brief Psychiatric Rating Scale and the Parkinson Psychosis Questionnaire. CBD also lowered the scores of the Unified Parkinson’s Disease Rating Scale, showing it could improve other aspects of the condition as well. CBD didn’t lead to any adverse effects. According to the researchers, “These preliminary data suggest that CBD may be effective, safe and well tolerated for the treatment of the psychosis in PD.”

In a double-blind study of 21 Parkinson’s patients without dementia or coexisting psychiatric conditions, the patients received either 75 mg or 300 mg/day CBD or a placebo.⁹ Although CBD did not lead to improvements in PD symptoms or neuroprotective effects, patients receiving 300 mg/day CBD were found to have a significantly better quality of life. The study authors believe this may have been due to CBD’s ability to calm the mind and boost mood along with its beneficial effects in psychosis.

Parkinson’s patients often experience a condition known as REM sleep behavior disorder (RBD).¹⁰ This condition is associated with vivid nightmares, and patients often act out their nightmares in their sleep, such as trying to run away from someone chasing them in their dreams. In a study of four PD patients, CBD quickly and significantly reduced the frequency of RBD-related problems without causing any side effects.¹⁰

The human studies conducted on CBD in PD showed that this phytocannabinoid may reduce non-movement-related symptoms of PD. However, in rodent models of PD, CBD has improved movement-related symptoms. For example, CBD stopped abnormal movements from occurring when rodents were given antipsychotic drugs known to cause rigidity of the body.^11,12

One way in which CBD may benefit PD is through its ability to protect the mitochondria, the powerhouses of the cells.¹³ Research shows that when the mitochondria are not working properly it can lead to the development of PD.¹⁴

CBD increases mitochondrial activity.¹³ Furthermore, in rats exposed to iron overload, which resembles neurodegenerative disorders, CBD reverses the damage that excess iron does to mitochondrial DNA.¹⁵

 

Huntington’s Disease

Huntington’s disease is an inherited neurological disorder caused by a mutation in the gene encoding the protein huntingtin. It’s characterized by involuntary movements (chorea) and cognitive problems. There’s a lot of reasons why CBD and other phytocannabinoids could play a role in supporting health in Huntington’s disease. Research in animals shows that endocannabinoid system activity is significantly reduced in HD, often at the early stages of the disease.^16,17

Studies in rodents also show CBD may keep brain cells healthy. In one study, researchers exposed striatal neurons—a type of brain cell affected in HD—to a mitochondrial toxin.¹⁸ This toxin causes changes similar to those that occur in HD. However, CBD protected the neurons from the toxin’s damaging effects. Many of the animal studies combined CBD with THC, the psychoactive component of marijuana. In these studies, the scientists gave the animals either the drug Sativex^® which is a combination of CBD and THC or a similar combination of phytocannabinoids. In these studies, the CBD/THC combination protected the animals’ neurons.^19,20

There aren’t a lot of studies in humans investigating whether CBD alone has a role to play in supporting the health of people with HD. In humans, researchers have studied CBD combined with THC in the drug Sativex® or synthetic cannabinoids. In HD, patients suffer from dystonia, involuntary muscle contractions leading to twitching or repetitive movements. One trial, which investigated several different types of pharmaceutical cannabinoids including Sativex® in seven HD patients, observed a lot of beneficial effects including improved motor skills and less dystonia.²¹ The CBD/THC combinations also improved the patients’ behavior. They were less irritable and apathetic. Plus, in some cases, they experienced less hypersalivation. Researchers are currently conducting a clinical trial of CBD combined with THC to see whether it can benefit people with HD. Results aren’t ready yet, but it will be interesting to see what the outcome will be.²²

To my knowledge, there was only one small trial of 15 patients with HD who were given CBD alone rather than administering this phytocannabinoid together with THC.²³ In this double-blind, randomized study the participants were given an average daily dose of about 700 mg/day for 6 weeks and then crossed over to a sesame oil placebo for six weeks. CBD was found to be safe, but it did not benefit the patients. A lot more studies need to be done before we can truly say whether CBD is effective.

It’s even entirely likely that when CBD is combined with other cannabinoids, such as in hemp oil, the hemptourage effect kicks in to produce better results. One review found that CBG, CBC, and CBDV were effective in rodent and cell culture models of HD.²⁴ CBG blocked the loss of neurons caused by a toxin and reduced the activity of genes linked to HD. CBG also reduced inflammatory markers. Plus, HD-related problems with movement improved in rodents given CBG

 

Autism

 

Autism Spectrum Disorder (ASD) is characterized by poor social communication, restricted and repetitive patterns of behavior, interests, or activities, and intellectual disabilities. People with ASD also often suffer from coexisting conditions such as sleep problems, epilepsy, and attention deficit/hyperactivity disorder.

There’s good reason why CBD should support the health of people with ASD. The endocannabinoid system of ASD patients with seizures, anxiety, cognitive problems, and impaired sleep often isn’t working the way it’s supposed to.²⁵

Additionally, compared with healthy controls, children with ASD have lower plasma levels of the body’s naturally produced endocannabinoid anandamide.²⁶ These low anandamide levels are thought to play a role in problems that ASD patients have in social interactions with other people.²⁷

There are many anecdotal reports that CBD works well in people with autism. Plus, as mentioned above, there’s strong justification why it would work in ASD. However, surprisingly, there aren’t a lot of studies backing up CBD’s use in ASD. Many of the studies that investigate CBD in autism used both CBD and THC. One study used cannabis with a high CBD content in 60 children with ASD who had severe behavioral problems.²⁸ In 61% of the children given the CBD-rich cannabis, parents rated behavioral problems much improved or very much improved.

The justification behind using CBD alone in autism comes from studies that show this phytocannabinoid improves many symptoms that occur autism. These studies did not investigate CBD in autism directly but rather explored its use in problems common to ASD and other disorders. For example, as we’ve covered in previous chapters, CBD reduces stress and calms anxiety in people giving speeches. It also improves sleep. In animal studies of schizophrenia, CBD stopped social withdrawal and improved social interaction and cognition.^29,30 In addition, in a mouse study of Dravet Syndrome (a severe type of epilepsy), both seizures and autism-like behaviors declined in the animals given CBD.³¹

 

Attention Deficit Hyperactivity Disorder

As the name of the disorder implies, people who have attention deficit/hyperactivity disorder (ADHD) have a hard time paying attention and are hyperactive. The disorder is also characterized by impulsiveness that interferes with a person’s ability to socialize or perform well at school or work. The Centers for Disease Control and Prevention estimates 6.1 million children and adolescents suffer from the disorder.³² An estimated 29.3% of children with ADHD will still have the condition when they become adults.³³

The neurotransmitter dopamine doesn’t send the messages it’s supposed to in people with ADHD. Normally, dopamine acts on CB₁ receptors in the endocannabinoid system. When dopamine doesn’t regulate the endocannabinoid system the way it should, it can lead to hyperactivity.³⁴

Much of the basis for using CBD in ADHD comes from studies where the phytocannabinoid improved symptoms similar to those suffered by ADHD patients, although the studies weren’t done in people suffering from ADHD. In previous chapters I discussed CBD’s ability to calm anxious feelings in people giving a speech, and earlier in this chapter I talked about CBD’s ability to improve sleep in PD patients. Researchers have studied CBD in combination with THC (Sativex^®) in 30 adults with ADHD.³⁵ In this randomized, controlled study, cognitive performance didn’t improve, but hyperactivity, impulsivity, and measures of inhibition were significantly better. A rodent study using CBD without THC also showed promise. In this study, CBD stopped hyperactivity and social withdrawal.³⁶

 

Epilepsy

Past animal studies and clinical trials have found that CBD can reduce seizures in a number of different types of epilepsy. For example, in a randomized, double-blind, placebo-controlled 14-week study of Dravet syndrome patients, CBD combined with anti-epileptic drugs led to more pronounced reductions in the frequency of convulsive seizures compared with a placebo.³⁷

In another study, researchers investigated the effects of either a placebo or cannabidiol together with standard antiepileptic medication in 225 patients with a severe type of epilepsy (Lennox-Gastaut syndrome).³⁸ In the double-blind, placebo-controlled trial, the subjects were divided into three groups that received either 20 mg per kilogram of body weight of a cannabidiol oral solution or 10 mg per kilogram or a matching placebo, given in two equally divided doses daily for 14 weeks. For 28 days before enrolling in the trial, all of the patients in the study had two or more drop seizures per week. Drop seizures—also called atonic seizures—are those that cause a loss of muscle strength and usually cause the patient to fall.

During the treatment period, median drop seizure frequency was reduced by 41.9% in the 20-mg cannabidiol group, 37.2% in the 10-mg cannabidiol group, and only 17.2% in the placebo group. There were mild adverse events in some of the patients, primarily those taking the highest dose, including sleepiness, decreased appetite, and diarrhea. Six patients in the 20-mg cannabidiol group and 1 patient in the 10-mg cannabidiol group discontinued the trial due to these effects. Liver enzymes were elevated in 14 patients who received CBD.

According to the study authors, “Among children and adults with the Lennox-Gastaut syndrome, the addition of cannabidiol at a dose of 10 mg or 20 mg per kilogram per day to a conventional antiepileptic regimen resulted in greater reductions in the frequency of drop seizures than placebo.”

Many of the more recent studies have used a highly purified form of CBD known as Epidiolex®. In one of these studies, children and adults with treatment-resistant Lennox-Gastaut syndrome (LGS) or Dravet syndrome (DS) who were also taking anti-epileptic drugs were given Epidiolex® in oral solution.³⁹ At the study’s start, parents and caregivers kept a record of  the types and number of seizures experienced. The patients were started out at a dose of 2-10 mg/kg/day. Their dose was then gradually increased up to a maximum dose of 25-50 mg/kg/day. At 12 weeks, CBD use was associated with a 50% reduction in median monthly major motor seizures and a 44% reduction in total seizures. Consistent reductions in both seizure types occurred through 96 weeks. A complete resolution of seizures occurred in 5% of the participants. CBD was safe, although minor adverse events like sleepiness occurred in 30% of the study subjects and 24% suffered from diarrhea. When the researchers followed up with the patients in two years, the Improvements remained.

The researchers concluded, “Overall, these results support previous observational and clinical trial data showing that add-on CBD may be an effective long-term treatment option for patients with LGS or DS.”

 

Schizophrenia

Schizophrenia is a disorder characterized by hallucinations, social withdrawal, and lack of motivation. It occurs in 1% of the population, but is more common in people with close relatives who had the disorder. While not traditionally considered a neurological disorder, recent evidence from scientific journals suggests that this disease may belong under that classification. For example, scientists have found that gene mutations in schizophrenia interfere with excitatory and inhibitory neurotransmission.⁴⁰ In other words, signals broadcast by brain chemicals are disrupted in this disease, leading to problems with brain function.

Studies have shown that an imbalanced endocannabinoid system is involved in schizophrenia. Levels of anandamide—an endocannabinoid naturally produced in the human body—are too low in people with psychotic symptoms.⁴¹ A double-blind, randomized, clinical trial showed what happens when CBD is given to schizophrenic patients with low anandamide.⁴¹ In 42 patients with schizophrenia, CBD was used at a dose of 200 mg per day to start and then increased by 200 mg per day until a daily dose of 200 mg four times daily (total 800 mg per day) was reached within the first week.⁴¹ CBD significantly increased serum anandamide levels. This increase in anandamide was linked to clinical improvement.

Although CBD hasn’t been found effective in all studies on its use in schizophrenia,⁴² there is still a lot of reason to believe CBD may have a role to play in the disorder. For example, in an exploratory double-blind trial, researchers randomized 88 patients with schizophrenia to receive either 1,000 mg/day of CBD or a placebo along with the antipsychotic medications the patients were already taking.⁴³ After six weeks, patients taking CBD had less psychotic symptoms such as hallucinations compared to the placebo. In addition, the treating physicians of participants in the CBD group were more likely to rate the patients as improved and as “not severely unwell.” Patients given the CBD also experienced improvements in cognitive performance and overall functioning, although these improvements didn’t reach statistical significance. The patients tolerated the CBD well and adverse events occurred at a similar rate in both the CBD and placebo groups.

 

Multiple Sclerosis

Multiple sclerosis (MS) is a chronic inflammatory and neurodegenerative disease associated with muscle stiffness, spasms, pain, and tremor. Nearly 1 million people in the United States suffer from this disorder, according to a study by the National Multiple Sclerosis Society.⁴⁴

The endocannabinoid system regulates the muscle spasms that occur in MS.⁴⁵ In an experimental study of MS and of MS tissue, local changes occurred in the endocannabinoid system in areas of MS lesions.⁴⁵ In addition, the endocannabinoid system controls the amount of neurodegeneration that occurs due to inflammation.⁴⁵

This is the reason why scientists started studying CBD together with THC in multiple sclerosis. The study results have been so promising that CBD plus THC in Sativex^® is an approved anti-inflammatory drug treatment against spasms in multiple sclerosis.^2,46,47 Some studies also suggest a CBD/THC combination may improve neuropathic pain in people with MS.⁴⁸

Other phytocannabinoids like CBG may also help people with MS. A review of the medical literature found that CBG reduced activity of the proinflammatory oxidative enzyme myeloperoxidase (MPO) in a rodent study.⁴⁹ Even though this study was done in animals with colitis, MPO is involved in other diseases such as multiple sclerosis.⁴⁹

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