Kava is a tropical plant whose underground stem is a drink that has the effect of altering the level of consciousness in religious and cultural ceremonies, and as a medicinal and social occasion, it acts like alcohol, allowing physical and mental relaxation
In empirical medicine, the benefits and side effects of kava are discussed in this article.
What is Kava?
Kava is a perennial shrub originating from tropical island regions in the western Pacific Ocean, the word Kava is mainly derived from Polynesian, meaning bitter.
The main active ingredient of Kavalactone is kavalactones, which is considered by modern research to have the following effects: anti-anxiety, anti-stress, sedative, analgesic, muscle relaxant, antithrombotic, neuroprotective, light anesthesia, sleep, antispasmodic and other effects. Note 8
Since the 1990s, Kava has been considered a natural alternative to sedatives and anxiolytics, but has been banned in some countries due to possible side effects (and has now been revoked in Germany due to insufficient evidence). Note 9
What are the recommended benefits of Kava?
1. Is it beneficial for generalized anxiety disorder?
Generalized anxiety disorder is a common mental disorder with a lifetime prevalence of 5.9%, characterized by excessive and inappropriate worry (not limited to a specific environment, and the condition lasts for more than 6 months). Note 1
Physical and mental symptoms that may occur include restlessness, fatigue, difficulty concentrating, irritability, muscle tension, sleep disturbances, palpitations, and respiratory distress.
A literature review and meta-analysis (12 studies) noted that kava is considered a promising treatment for generalized anxiety disorder, but there is no clear evidence of improvement over placebo (not statistically significant). Note 2
*Conclusion: Up to now, the relevant results of the use of Kava in the treatment of generalized anxiety disorder are still inconsistent, and there are both positive and negative opinions, which need to be further confirmed by more large studies
2. Beneficial for insomnia
Insomnia is the most direct factor in the reduction of quality of life, and the main features are difficulty falling asleep, often waking up at night, lack of sleep, premature awakening, difficulty in recovering mentally and other states.
The prevalence of insomnia can reach 15% of the population, especially divorce, separation or widowhood, the elderly, women, and comorbidities or related psychiatric diseases are the most common, and long-term may cause type 2 diabetes, metabolic syndrome, obesity, neurodegenerative diseases and other diseases.
A 22-week study of 24 patients with stress-induced insomnia found that Kava extract (LI 150) helped improve stress and insomnia. Note 3
A multicenter, randomized, placebo-controlled, double-blind clinical trial (4-week patient with insomnia due to anxiety, nervousness, and restlessness) found that oral kava extract (WS 1490) improved anxiety and sleep quality. Note 4
*Conclusion: For stress and anxiety-induced insomnia, the use of Kava extract may be positive, but more large studies are needed
3. Improve cognitive ability
Changes in cognitive function are the most common changes in the aging process, while language ability, some numerical abilities, and general knowledge are less affected by aging.
Some cognitive abilities, such as memory, executive function, processing speed, and reasoning, gradually decrease with aging, but do not reach dementia, which is generally called mild cognitive dysfunction.
It has been observed that about 10% to 15% of people with mild cognitive impairment will deteriorate into dementia (Alzheimer’s disease) each year. Note 5
A double-blind crossover study (5-day, 12 healthy men) showed that the use of Kava extract had the effect of increasing recognition rate on recognizability tests compared with placebo and showed a large difference in event-related potential. Note 6
*Conclusion: Kava extract may help improve cognitive function, but it is limited by the small sample size and needs to be further validated
Are there any side effects of kava?
Up to now, the side effects or adverse reactions reported by kava-related products include: liver damage, headache, dizziness, tiredness, rash, stomach upset, diarrhea, restlessness, loss of appetite, partial hearing loss, hair loss, dry skin, etc
Among them, liver damage is the most important side effect, but there is no clear evidence to confirm that there is a direct causal relationship between the two, which may be related to the excessive use of related products, the difference in extraction medium (more negative cases of ethanol or acetone, less water extract), combined alcohol or other drug use, variety, raw material adulteration, and raw material use site difference
* The use of peeled rhizomes parts of the product is safer, leaves, stems, branches, contains more alkaloids, has high toxicity
Safety precautions (7 contraindications to use)
1. Do not use if you are pregnant, nursing or have poor liver and kidney function (may cause unknown risks)
2. Avoid using alcoholic beverages to increase the risk of liver damage
3. Although there is no clear evidence, it is best not to take it before behaviours that require high concentration, such as driving a car or operating a machine, which may affect concentration. Note 7
4. Moderate use of kava standard preparations (WS 4 or LI 1490) in the short term (less than 150 weeks), although seemingly safe (no obvious side effects), it is still recommended to confirm with a doctor or pharmacist before use and under close supervision
5. Do not use by patients with Parkinson’s disease (may cause symptoms to worsen)
6. Discontinue use <> weeks before surgery (because kava may affect the effectiveness of anesthesia and other drugs)
7. Do not use it with drugs that need to be acted by Cytochrome P450 enzyme and P-glycoprotein mechanism, which may affect the efficacy of drugs and increase unknown risks, common related drugs are
Diazepam, Caffeine, Amitriptyline, Imipramine, Propranolol, Fluoxetine, Haloperidol, Morphine, β Beta-blockers, amitriptyline, celecoxib, diclofenac, ibuprofen, warfarin, acetaminophen, lovastatin, ketoconazole, etoposide, Erythromycin, corticosteroids, vincristine, fexofenadine, cimetidine, cisapride