Kava is a plant traditionally used as an intoxicating beverage by the indigenous people of the South Pacific. Kava can also be used to help with anxiety, stress, insomnia, and other disorders. However, high doses of kava may cause liver damage and the plant should not be taken in combination with alcohol or other psychotropic medications. Read on to learn more about the potential health benefits and side effects of kava. What Is Kava?
Kava ( Piper methysticum ) extract is traditionally prepared from a combination of kava root and water and is commonly used as a psychotropic beverage in the South Pacific.
Forms of kava products include [ 1 ]: Root extract
Kava tea, kava root extract, and capsules generally produce mild effects, while tinctures and powders are stronger. Kava paste produces the strongest effects, since the product is highly concentrated.
Importantly, several cases of liver damage and even death from taking kava (possibly due to the presence of the root and stem peelings in the kava product, instead of only the peeled root) have been reported. For this reason and its potential for abuse, kava is banned in Europe, the UK, and Canada [ 1 , 2 ].
Kavalpyrones and chalcones are the two main active compound classes of kava extract [ 3 , 4 ]: Kavalpyrones (methysticin, dihydromethysticin, yangonin, dihydrokavain, and kavain) produce muscular relaxation and calming effect.
Chalcones (flavokawain A, B, and C) have potential antioxidant, anti-inflammatory, antimicrobial, and anticancer effects.
Mechanisms of Action
Kavain and methysticin block sodium ion channels, leading to a decrease in cell excitability. By blocking sodium channels, kavain also reduces excitatory neurotransmitter release. Kavain and methysticin decrease stimulatory pathways, possibly leading to a calming effect [ 5 , 6 , 7 ].
Yangonin, kavain, dihydrokavain, methysticin, dihydromethysticin, and kava pyrones increase GABA in the brain (hippocampus, amygdala, and medulla oblongata). When GABA-A receptors are activated, neurons are inhibited, which may have sedative and anti-anxiety effects [ 6 , 7 , 8 ].
Multiple kavalactones (desmethoxyyangonin, methysticin, yangonin, dihydromethysticin, dihydrokavain, and kavain) inhibit monoamine oxidase B. Kavalactones prevent the enzyme MAOB from removing neurotransmitters norepinephrine , serotonin , and dopamine from the brain [ 6 , 7 , 9 ].
Kavain, desmethoxyyangonin, and methysticin increase noradrenaline , serotonin , and dopamine . Low levels of noradrenaline, serotonin , and dopamine are associated with depression , anxiety, ADHD, and other disorders [ 5 , 6 , 7 , 10 ]. Snapshot
May reduce anxiety
May improve sleep disorders and depression
May improve mood symptoms associated with menopause
Insufficient evidence for many benefits
Several cases of liver damage and even death reported
High potential for abuse
Banned in several countries High risk of drug interactions Health Benefits Likely Effective for: Anxiety Multiple human studies showed that kava improved anxiety , regardless of the symptoms and type of disorder (nonspecific anxiety, tension, agitation, agoraphobia, specific phobia, or general anxiety disorder) [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ].In a clinical trial on 129 people with generalized anxiety disorder, kava extract (400 mg) was as effective as two anti-anxiety drugs (opipramol 10 mg and buspirone 100 mg) [ 12 ]. Kava activates GABA-A receptors, which produces a calming effect . Kava prevents a decrease in norepinephrine , serotonin, and dopamine levels by inhibiting monoamine oxidase and relaxes muscles by decreasing beta adrenaline receptor activity [ 7 , 6 , 1 , 18 ].All in all, the evidence suggests that kava may help with anxiety. Remember that this supplement is not approved by the FDA for this purpose and is even banned in some countries due to its potential for abuse and risk of liver damage. Discuss with your doctor if it may be helpful in your case and always take it as recommended by them. Insufficient Evidence for: 1) Sleep Disorders Kava reduced stress and improved sleep quality in 24 patients suffering from stress -induced insomnia. 61 patients suffering from sleep disturbances associated with anxiety, tension, and restlessness were also effectively treated with kava extract [ 19 , 20 ].Kava’s potentially sedative effects are due to the blocking of sodium and calcium ion channels, increased neurotransmitter binding to GABA-A receptors, inhibition of monoamine oxidase B, and an increase of the neurotransmitters noradrenaline and dopamine [ 1 , 21 ].Although promising, the evidence to support the use of kava in sleep disorders is insufficient. More clinical trials on larger populations are needed to confirm these preliminary results. 2) Depression In a clinical trial on 60 people with generalized anxiety disorder, oral kava extract (250 mg kavalactones per day) reduced both anxiety and depressive symptoms [ 2 ].Its combination with Saint John’s wort improved depression (but not anxiety or quality of life) in a small trial on 28 people with major depressive disorder [ 2 ].Kava induced a pleasant mental state while reducing fatigue and anxiety in human and animal studies. Kavalactones in kava increased dopamine, serotonin, GABA (only slightly), and decreased glutamate in cell models [ 22 , 23 , 24 ].Again, the results are promising but only two small clinical trials have been conducted. Further clinical research is required to confirm the potential benefits of kava in people with depression. 3) Menopausal Symptoms Perimenopause and menopause symptoms include hot flashes, night sweats, insomnia, and increased anxiety and irritability.Kava improved anxiety, depression, irritability, and insomnia in 3 clinical trials on 120 perimenopausal and menopausal women. It activated GABA-A receptors, inhibited monoamine oxidase-B, and increased dopamine levels in the brain [ 25 , 26 , 27 ].All in all, there is insufficient evidence to claim that kava helps with mood symptoms of menopause and perimenopause. Larger, more robust clinical trials are needed to validate these findings. 4) Brain Function A single dose of kava extract (300 mg) improved accuracy and performance in attention, visual processing, and working memory tasks in […]