The legalization of medical cannabis has become a hot topic of discussion in many countries around the world, in fact, hemp has historically been a high economic yield crop, in addition to fiber can be used as rope or weaving, seeds can also be squeezed for oil, and has a wide range of medical value, and since the discovery of its main components Cannabidiol (CBD) and tetrahydrocannabinol (THC), a variety of medical uses have slowly emerged.
What are the benefits of CBD in empirical medicine? Are there any side effects or contraindications? See text analysis for details.
What is CBD?
CBD, short for cannabidiol, is one of nearly a hundred active ingredients in the cannabis plant, unlike the most prestigious tetrahydrocannabinol (THC), it does not produce euphoria, does not cause dependence or abuse (common commercially sold forms are gels, gummies, CBD oils, powders, extracts, etc.)
Due to its potential multiple therapeutic properties and good safety and tolerability, CBD is currently one of the most studied cannabinoid substances (cannabinoid), with anti-inflammatory, antispasmodic, antioxidant, antiemetic, anxiolytic, antipsychotic and other potential benefits, and has therapeutic effects on some refractory diseases (such as: intractable epilepsy, Parkinson’s disease, anxiety, etc.), so it has gradually attracted attention.
CBD can interact positively with the endocannabinoid system, an important physiological system that affects various functions of the body, including brain plasticity, motor control, memory, cognition, stress, emotional response, inflammation, appetite regulation, pain, learning, and memory.
*Tetrahydrocannabinol (THC) is a cannabis-like substance in marijuana that has long been considered the main psychoactive component, that is, hallucinogenic and addictive.
What are the proven benefits of CBD/cannabidiol?
1. CBD is beneficial for insomnia management
Insomnia has gradually become a common phenomenon in fast-paced urban life, occurring in individuals of different ages, with about 33 to 50 percent of adults experiencing insomnia, accounting for almost half of all sleep disorders.
Insomnia is defined as a subjective feeling of difficulty initiating sleep (sleep latency longer than 30 minutes), duration, and consolidation, resulting in adequate sleep opportunities but unsatisfactory sleep quality.
A systematic review (34 studies) noted that CBD alone or in combination with an equal amount of THC may help relieve insomnia symptoms. Note 1
*Conclusion: CBD may have a positive effect on insomnia, but due to the low quality of the included studies, more studies are needed to evaluate the efficacy and safety in patients with insomnia
2. CBD is beneficial for post-traumatic stress disorder
Post traumatic stress disorder is a mental illness that can occur after experiencing one or more unusual threats or terrorist events, such as a car accident, physical assault, sexual assault, or combat trauma.
Worldwide, the estimated 12-month prevalence is 3% to 4%. In conflict-affected areas, prevalence is much higher, between 13 and 25 percent, reaching more than 50 percent among survivors of sexual assault.
A randomized, double-blind controlled trial (33 patients diagnosed with PTSD) showed that oral CBD (dose 300 mg) reduced cognitive impairment and anxiety caused by recalling traumatic events compared with placebo in patients with nonsexual trauma. Note 1
However, in patients with sexual trauma, differences measured between the two groups (CBD and placebo) were not significant, including: anxiety, sedation, cognitive impairment, and malaise.
*Conclusion: Oral CBD may be a positive help for non-trauma-related post-traumatic stress disorder, but limited by the fact that the study measured many outcomes and did not correct multiple comparisons, this increases the likelihood of false positive results and needs to be further validated by more studies
3. CBD assists in the treatment of psoriasis
Psoriasis, also known as psoriasis or psoriasis, is a common chronic inflammatory skin disease characterized by localized or widespread squamous erythematous plaques, with rapid proliferation of epidermal keratinocytes in the basal layer as the main pathological feature, with global prevalence ranging from 0.6% to 4.8%. The incidence peaks between the ages of 15 and 30.
It not only affects the skin and joints, but also causes metabolic syndrome, obesity, cardiovascular disease, mental illness, etc.. In addition, psoriasis can also cause damage to the patient’s body, affecting the patient’s appearance, social activities and quality of life.
One randomized placebo-controlled study (12 weeks, 51 psoriasis participants) noted that topical CBD treatment significantly reduced the severity score of psoriasis/psoriasis lesions, as well as fewer non-responsive lesions and a greater proportion of lesions disappeared completely compared with placebo. Note 1
*Conclusion: For the adjuvant treatment of psoriasis, topical CBD may bring positive help, but limited by the small sample size, more studies are still needed for further verification
4. CBD is beneficial for COVID-19
The COVID-2 pandemic, caused by coronavirus type 2 (SARS-CoV-19), has brought unprecedented challenges to global health care systems, mainly through direct contact with aerosols/droplets from infected people, which enter the body through epithelial cells of the tongue, bronchi, and lungs after attaching to angiotensin-converting enzyme 2 (ACE2).
In most symptomatic patients, symptoms are usually mild and include fever, shortness of breath, cough, fatigue, loss of smell, and muscle pain, but the risk of severe disease increases with gender, age, chronic illness, smoking.
A randomized, double-blind, placebo-controlled trial (14-day trial of 105 patients with mild to moderate COVID-19 receiving standard care) noted that oral CBD (300 mg per day) failed to alter clinical progression and did not significantly improve in measures such as mean time to symptom relief. Note 1
*Conclusion: So far, oral CBD has not been helpful in the treatment of COVID-19, and more studies are needed to further validate
5. CBD is beneficial for ulcerative colitis
Ulcerative colitis, a chronic inflammatory bowel disease (estimated prevalence of 240 per 100,000), is often caused by rectal bleeding, diarrhea, pain, fatigue and weight loss, and an increased risk of bowel cancer.
Treatment includes aminosalicylic acid, glucocorticoids, immunosuppressants, and anti-TNF drugs, however, some patients are resistant to existing standard therapies and therefore require alternative therapies.
A Cochrane Database of Systematic Reviews (2 randomized controlled trials, 92 participants) noted that the efficacy and safety of cannabis and cannabidiol in patients with active ulcerative colitis could not be reliably drawn, and there was no evidence for remission maintenance. Note 1
*Conclusion: The effects of cannabis and cannabidiol on ulcerative colitis are uncertain and limited by small sample sizes, and more large studies are needed
6. CBD is beneficial for Dravet syndrome
Dravet Syndrome, also known as severe infantile myoclonic epilepsy of infancy, is a rare early-onset inherited epilepsy syndrome originally discovered by Charlotte Dravet in 1978 and renamed Dravet syndrome in 1989.
It is characterized by initial febrile or afebrile seizures in normally developing infants, usually progressing to status epilepticus, followed by convulsive seizures, and complex partial seizures. In adulthood, it presents with persistent motor and cognitive dysfunction.
A systematic literature review and meta-analysis (3 randomized placebo-controlled trials with 359 participants in Dravet syndrome) noted that CBD-adjunctive therapy (Epidiolex (oral doses of 10 and 20 mg/kg daily) reduced the frequency of convulsive seizures, but also observed mild to moderate adverse events. Note 1
*Convulsive seizures is clinically defined as rhythmic tics lasting less than 5 minutes. It can be local (affecting one limb or one side of the body or face) or systemic (affecting the entire body).
*Conclusion: In patients with Dravet syndrome, adjuvant therapy with CBD oil (cannabidiol) may reduce tic seizures, but limited by small sample sizes, more studies are needed to confirm its clinical benefit
7. CBD is beneficial for Raiger syndrome
Lennox-Gastaut syndrome is a severe epileptic and developmental encephalopathy that usually appears at age 7 years, peaks at age 3 to 5 years, and has an incidence of about 2 cases per 100,000 people.
Drop seizures, a characteristic of this disorder, is a spasm that causes sudden loss of strength of muscles (involving the entire body, torso, or head), usually kept awake, can lead to falls, injuries, falls on chairs, or impact on the surface of the head, often resulting in serious injuries, and may be accompanied by cognitive and intellectual impairment
A systematic literature review and meta-analysis (2 randomized placebo-controlled trials with 396 participants in Raiger syndrome) noted that adjuvant CBD therapy (10 to 20 mg/kg daily) reduced atonic and non-atonic seizure frequency, and that mild to moderate adverse events were observed: drowsiness, decreased appetite, diarrhoea, and increased serum aminotransferases. Note 2
*Conclusion: For patients with Reig’s syndrome, the use of CBD adjuvant therapy may reduce seizures, but limited by the small sample size, more studies are needed to confirm its clinical benefit and safety
8. CBD is beneficial for schizophrenia
Schizophrenia, also known as schizophrenia, is a highly heterogeneous mental illness that has profound effects on patients. Usually occurring in early adulthood or late adolescence (affecting approximately 0.3 to 0.7% of adults), symptoms are divided into three dimensions: positive (eg, delusions, hallucinations), negative (eg, emotional retardation, anhedonia), and cognitive symptoms (eg, attention, memory, executive function).
Current pharmacological therapy is mainly based on dopamine blockade, the effect of which is limited to positive symptoms. In addition, two-thirds of patients experience adverse effects on dopaminergic therapy, so alternative and more effective pharmacological interventions are urgently needed to reduce the burden.
A systematic literature review and meta-analysis (including three randomised controlled trials) noted that in one study, CBD oil was compared with amisulpride as a single treatment, but there was no statistically significant difference in overall efficacy between the two, and no data on cognition. Note 3
Two other studies evaluated CBD oil as an add-on treatment versus placebo and found no significant difference in overall efficacy and cognition.
*Conclusion: Up to now, the evidence on the efficacy and safety of CBD oil in patients with schizophrenia is not sufficient, and more studies are needed to further confirm it
9. CBD is beneficial for Parkinson’s disease
Parkinson’s Disease is a disease caused by basal ganglion abnormalities in the extrapyramidal system, with a prevalence of 60% over 2 years of age, a male-to-female ratio of about 3:2, and a 6-fold increase in the incidence of dementia.
Parkinson’s disease is characterized by loss of dopaminergic function and decreased motor function (including resting tremor, bradykinesia, muscle stiffness), and the causative agent is related to exposure to pesticides and other toxic substances, family history, and oophorectomy, but aging is the most important factor.
A double-blind controlled study (in 21 Parkinson’s disease patients without dementia or other psychiatric conditions) noted that the use of cannabidiol (CBD) improved quality of life measures compared with placebo (but there was no significant difference in motor symptoms and neuroprotective benefits). Note 4
*Conclusion: Cannabidiol (CBD) may improve quality of life in patients with Parkinson’s disease without psychiatric symptoms, but not significantly improve motor function
10. CBD is beneficial for cardiovascular function
Cardiovascular disease is currently the most burdensome disease in the healthcare system, and about 90% of common myocardial infarctions are associated with attributable risk in the population, including cholesterol ratio, smoking, diabetes, hypertension, abdominal obesity, psychoemotional factors, fruit/vegetable intake, physical activity and alcohol consumption.
Cardiovascular disease is expected to surpass infectious diseases as the leading cause of human disability and death globally by 2020, growing from 25% in the 1990s to 40% in 2020.
A systematic literature review and meta-analysis (22 studies) showed that the use of CBD did not have a significant effect on blood pressure and heart rate improvement in the controlled state, but it had the effect of lowering blood pressure and heart rate in stressful conditions, and was found to increase cerebral blood flow in the Ischemia reperfusion injury model. Note 5
*Conclusion: Cannabidiol may have a positive effect on cardiovascular function in animal models, but the relevant human evidence is still insufficient and needs to be verified
Are there any side effect of CBD/Cannabidiol?
LIMITED STUDIES HAVE FOUND THAT CANNABIDIOL (CBD) IS A POTENTIALLY SAFE SUBSTANCE FOR HUMANS, WITH NO INTOLERANCE OR TOXICITY FOUND WHEN USED AT APPROPRIATE DOSES
Side effects or adverse reactions that have been reported include the following: Note 1
Tiredness, diarrhea, dry mouth, low blood pressure, mild headache, dizziness, drowsiness, sedation, changes in appetite, anxiety, irritability, weight changes, respiratory infections
Suicidal thoughts and suicidal behavior, rashes, insomnia, sleep disruption, poor sleep quality, convulsions, anemia, increased intraocular pressure, fever, fatigue, allergic reactions etc.
Safety precautions
1. Do not use by pregnant women, lactating women, and children under 2 years old (due to unknown safety)
2. CBD should be used with caution when used with drugs that may cause liver damage, or in people with pre-existing liver damage (such as alcoholics or hepatitis patients), which may increase the risk of liver damage, especially transaminase (Transaminase) elevation, such drugs include: antiepileptic drugs, antipsychotics, acetaminophen, certain antibiotics (such as amoxicillin, nitrofurantoin), antifungals, and verapamil etc..
3. CBD use may cause urine drug tests to be THC positive. Note 1
This is because products containing CBD may contain trace amounts of THC or be improperly labeled, and to avoid testing positive for THC, CBD products should be purchased from a reliable source to ensure that the product does not contain any THC.
4. If the liver and kidney function is poor, please consult a medical professional before use (due to unknown safety)
5. Do not use it in combination with drugs, because it may inhibit the enzyme related to metabolizing drugs in the liver (cytochrome P450, which is responsible for more than 60% of the metabolism of prescription drugs), which will affect the effect of drugs and cause unknown risks
6. High dose use may cause tremor and muscle motor symptoms worsening in Parkinson’s disease patients
7. Patients with immunocompromised (such as AIDS, diabetes and Down syndrome) or taking immunosuppressants should not use it, as CBD (cannabidiol) may suppress immune function and increase the risk of infection
8. High doses of CBD may trigger anxiety and irritability
9. In several trials, it has been found that the combination of CBD oil with the anti-epileptic drug: valproate, may cause liver damage, the risk increases with increasing doses, and valproic acid is one of the drugs known to cause liver damage. Note 6
10. Do not use for patients with low blood pressure or taking blood pressure lowering drugs, which may cause low blood pressure (because CBD may have a blood pressure-lowering effect)
What is the difference between CBD oil and hemp seed oil?
First of all, the general cannabis plant can be roughly divided into cannabis (Cannabis or Marijuana) and hemp (hemp, also known as hemp or industrial hemp), both of which are two varieties of the same cannabis plant
The biggest difference between the two ingredients is the content of THC and CBD:
Cannabis or marijuana usually contains more THC (tetrahydrocannabinol, about 5% to 20%) and a small amount of CBD (cannabidiol, averaging less than 0.15%)
Hemp (hemp) contains very little THC (less than 0.3%) and more CBD (cannabidiol) (at least 12% to 18%)
CBD oil and hemp seed oil are mostly extracted from hemp (hemp), which comes from different parts of hemp plants
CBD oil is produced using the stems, leaves, and flowers of the hemp plant, which contain a higher concentration of CBD, a compound with many potential health benefits.
Hemp seed oil, as the name suggests, is extracted from the seeds of the cannabis plant, which generally does not contain THC (tetrahydrocannabinol) and CBD (cannabidiol)
Hemp seed oil is considered a healthy, nutrient-dense oil because it provides high levels of monounsaturated fats (omega-3/omega-6 fatty acids, linolenic acid)
Is CBD legal in the US? Can I buy it for my own use?
Currently, hemp (Hemp)-derived CBD products (with less than 0.3% THC content) are legal to use in all U.S. states in the United States, provided they are obtained from licensed growers. Marijuana-derived CBD products are illegal in most states, and some require medical approval to be used legally
Is CBD legal in Taiwan? Can I buy it for my own use?
If the public prescribes such drugs after diagnosis and assessment by a physician, they can apply for the import of cannabidiol (CBD) drugs for personal use in accordance with the “Measures for the Administration of Drug Sample Gifts”.
If the drug containing cannabidiol (CBD) contains tetrahydrocannabinol (THC) or products made from mature cannabis stems and seeds, and the THC content exceeds 10ug/g (10ppm), it is a second-class controlled drug, according to the professional evaluation opinions of experts on the existing clinical literature, only Dravet syndrome and Lennox-Gastaut syndromes pediatric patients with intractable epilepsy have the need to use such cannabinoid preparations. It is recommended that after the doctor’s diagnosis and evaluation, the application may be submitted by the teaching hospital or psychiatric teaching hospital above the regional hospital in accordance with the “Regulations on the Administration of Controlled Drugs” and the “Measures for the Approval of the Manufacturing and Import of Specific Drug Items”.
Is CBD legal in Hong Kong? Can I buy it for my own use?
In Hong Kong, CBD and tetrahydrocannabinol (THC) are dangerous drugs regardless of their concentrations, which are controlled under the Dangerous Drugs Ordinance and the manufacture, import, export, supply, sale, possession and trans-shipment of CBD are prohibited except for those permitted by the Department of Health, and any violation is a criminal offence