How safe is kava for anxiety, stress, insomnia and relaxation?

Kava has been a drink for thousands of years in the Pacific Islands. Its effects are similar to alcohol. People use kava for many reasons, in particular stress, anxiety, insomnia (sleeplessness), relaxation, improving mood, and as a social and ceremonial drink.

Some countries have taken kava off the market because it might cause liver damage. Many experts are unsure about kava’s safety, and whether kava alone, or in combination with other drugs/herbs or pre-existing health problems, could be dangerous.

A recent world-first Australian study found kava is, according to its researchers, “safe and effective in reducing anxiety”, and reduces depression. Lead researcher Jerome Sarris said, “We’ve been able to show that Kava offers a natural alternative for the treatment of anxiety, and unlike some pharmaceutical options, has less risk of dependency and less potential of side effects.”

The type of kava extract used in this study was water-soluble, like the type traditionally prescribed in the Pacific Islands. The kava extracts used in other studies of kava, that found the plant may be unsafe, were extracts that might cause liver problems.

“When extracted in the appropriate way, Kava may pose less or no potential liver problems. I hope the results will encourage governments to reconsider the ban,” Mr Sarris said.

Like most supplements, kava can interact with some medications and it can have side effects.

What is kava and how is it used?
How does kava work?
What is kava taken for?
What evidence is there that kava works?
Does kava have any withdrawal symptoms?
Does kava have any side effects?
What medications can kava interact with?
Who should avoid taking kava?

What is kava and how is it used?

Kava is a shrub that grows in the Pacific Islands. It belongs to the pepper family.

Traditionally kava root is crushed, ground or powdered, then added to water and drunk like tea. Kava is also available in capsules, tablets and liquid extracts.

In some parts of the world kava roots are chewed for their healing qualities.

Drug Info says that in some Pacific Island countries, such as Fiji, Vanuatu and Papua New Guinea, kava drinking is an important cultural practice. It strengthens social ties among groups, helps reaffirm status and rank in the community, and is believed to help people communicate with the spirit world.

Many Pacific Islanders who have settled in Australia continue to drink kava. In recent decades other Australians have also started drinking kava in a similar way to alcohol, and use products containing kava.

How does kava work?

Kava might affect the level of neurotransmitters in the body. Neurotransmitters are chemicals that carry messages between nerve cells. Some neurotransmitters that kava can affect include noradrenaline, GABA and dopamine. These all affect our mood.

Chemicals in kava can, for example,:

• help us relax
• reduce anxiety
• improve mood, so boost happiness and contentment
• make us sleepy
• relax muscles
• relieve pain
• reduce convulsions (fits)
• act as diuretics (rid the body of excess water)

What is kava taken for?

Kava has been used for many things, especially relaxation and to help treat insomnia, stress and anxiety.

What evidence is there that kava works?

The University of Queensland conducted a 3-week placebo-controlled, double-blind study of a water-soluble extract of kava. Sixty adults with anxiety took part in the study. The group that took the kava were less anxious and less depressed than the group that took the placebo (dummy) pill. The study’s researchers said this type of kava extract “… was found to be safe, with no serious adverse effects”, and was not toxic to the liver.

The UMMC says some clinical studies have found that kava treats the symptoms of anxiety. In a review of seven scientific studies, researchers concluded that a standardized kava extract was better than a placebo in treating anxiety.

A study found that kava improved symptoms of anxiety after only one week of treatment.

Kava might be as good as some prescription anti-anxiety medications, according to another study.

Kava and diazepam (Valium) cause similar changes to brain waves. They probably both work in the same way to calm the mind.

A 2004 study found that 300 mg of kava might improve mood and mental performance. This is important because some prescription drugs used to treat anxiety, such as benzodiazepines (like Valium and alprazolam or Xanax), tend to decrease mental function.

Wong says that in 2003 a review by the Cochrane Collaboration examined 11 studies of kava (with a total of 645 people) to see how the plant compared to a placebo in treating anxiety. The researchers concluded that kava “appears to be an effective symptomatic treatment option for anxiety”, but that it seemed to be a small effect.

The UMMC says kava might help improve sleep quality and decrease the amount of time needed to fall asleep, but more studies are needed to say for sure. Kava is not the best choice for treating insomnia because of concern about its safety.

Does kava have any withdrawal symptoms?

The Better Health Channel claims there is no evidence that people who often drink large amounts of kava become dependent. There doesn’t seem to be a risk of withdrawal if a person suddenly stops taking kava. Medical supervision is, however, recommended.

Does kava have any side effects?

The University of Queensland found that a water-soluble kava extract – like the type used traditionally in the Pacific Islands – is safe and effective for treating anxiety and depression. People have had less side effects from this type of kava than from orthodox anti-anxiety medication.

Drug Info says chronic or heavy use of kava might cause:

• bloodshot eyes
• chest pain
• dry and scaly skin
• extreme tiredness
• high blood pressure
• increased risk of infection
• irreversible liver and kidney damage
• loss of muscle control
• malnutrition
• severe weight loss
• shortness of breath
• stomach upset

Drug Info warns that high use of kava has been linked to mood swings and apathy. Mental problems such as depression and schizophrenia might be worsened.

Other possible side effects of kava can include:

• brown urine
• bruises
• dizziness
• headaches
• indigestion
• loss of appetite
• mouth numbness
• raised body temperature
• sight problems
• tremors
• restlessness
• unusual bleeding
• vomiting
• yellowing of the eyes or skin (jaundice)

Although rare, reports have linked kava with liver toxicity, including hepatitis, cirrhosis, and liver failure, says Wong. Clinical trials have not, however, found liver toxicity. Liver reactions appear to be linked to, for example, pre-existing liver disease, use of alcohol, and high doses of kava.

The Better Health Channel says that in 2003 products containing kava were banned in most European countries because of concerns about its possible toxic effects on the liver. In Australia all products containing kava were temporarily withdrawn after the death of one person from liver failure.

After a review by the Therapeutic Goods Administration in 2003, kava is available in Australia in restricted doses as supplements and teabags.

The UMMC says kava is available in the United States, but the Food and Drug Administration (FDA) issued a consumer advisory in March of 2002 regarding the “rare” but potential risk of liver failure associated with kava-containing products.

The UMMC also states that:

Because it is impossible to say what – if any – dose of kava might be safe, you should not take kava unless you are under a doctor’s close supervision.

What medications can kava interact with?

The UMMC says:

Do not take kava unless you are under the supervision of a doctor, especially if you are being treated for any disease.

Do not take kava with any prescription and non-prescription medications.

Kava might interact with the following to cause health problems:

• alcohol – do not take kava with alcohol
• anti-anxiety drugs
• anticonvulsants, such as phenytoin (Dilantin) for seizures
• the antidepressant drugs monoamine oxidase inhibitors (MAOIs)
• antipsychotic drugs
• drugs for insomnia (sleeplessness)
• Levodopa (L-dopa) for Parkinson’s disease
• diuretics (water pills), which help rid the body of excess water
• phenothiazine drugs for schizophrenia
• any herb or drug that affects liver function
• any drugs that affect blood clotting, such as Coumadin (warfarin) or aspirin
• any drugs that affect dopamine levels

Who should avoid taking kava?

Experts recommend that the following people should not take kava:

• pregnant women
• breastfeeding mothers
• children
• people with bleeding problems, because kava might lower blood pressure and interfere with blood clotting
• people with Parkinson’s disease, because it might worsen symptoms
• people about to have surgery (within 2 weeks of surgery)
• people with heart, liver or kidney problems
• people about to drive and/or use machinery
• anyone taking therapeutic drugs

written by Nyomi Graef

updated 25 September, 2012

References:
Kava, 2010, Better Health Channel, State Government of Victoria,
http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Kava

Kava, 2010, Wikipedia,
http://en.wikipedia.org/wiki/Kava

Kava, 2009, WebMD,
http://www.webmd.com/vitamins-supplements/ingredientmono-872-KAVA.aspx?activeIngredientId=872&activeIngredientName=KAVA

Kava, 2006, National Center for Complementary and Alternative Medicine, National Institutes of Health,
http://nccam.nih.gov/health/kava

Kava facts, 2010, Drug Info, State Government of Victoria,
http://www.druginfo.adf.org.au/drug-facts/kava

Kava kava, 2010, University of Maryland Medical Center,
http://www.umm.edu/altmed/articles/kava-kava-000259.htm

Kava (piper methysticum) – oral , 2010, MedicineNet.com,
http://www.medicinenet.com/kava_piper_methysticum-oral/article.htm

Sarris, J et al., 2009, The Kava Anxiety Depression Spectrum Study (KADSS): a randomized, placebo-controlled crossover trial using an aqueous extract of Piper methysticum, Psychopharmacology, Vol. 205, Iss. 3, 399-407,
http://www.springerlink.com/content/d067511634876461/

UQ research finds kava is safe and effective, 2009, The University of Queensland, Australia,
http://www.uq.edu.au/news/?article=18193

Winter Griffith, H, 1995, The Vitamin Fact File, London, UK: Diamond Books

Wong, C, 2010, Kava Kava, About.com,
http://altmedicine.about.com/od/kava/p/kava.htm