Kava (Piper methysticum)
Kava (also known as kava-kava) comes from the root of a plant grown in the Pacific Islands. This bitter-tasting root has been used for centuries by the Pacific Islanders to celebrate special occasions. It has somewhat of an intoxicating effect and creates a feeling of relaxation, without hang-over effects as shown with alcohol. The kavalactones are the active ingredients that act on the central nervous system to cause relaxation. Kava is still used today with Americans spending about $30-$50 million dollars on kava supplements every year to help with anxiety problems or insomnia.
Claimed Health Benefits
-
Helps alleviate anxiety
-
Relieves headaches
-
Helps induce sleep
-
Antidepressant
-
Helps with hot flashes associated with menopause
Food Sources
Kava beverage (consumed in the Pacific Islands)
Dose
Kava supplements should contain 50-150mg of kavalactones. A dosage of 100mg kava with a standardized 70% kavalactone concentration taken 1-3 times daily should reduce symptoms of mild anxiety.
Evidence for Health Benefits
-
A study looking at the affects of kava on anxiety disorders divided 58 patients into 2 groups. One group was supplemented with 100mg kava extract and the other group was given a placebo. Both groups had to take their assigned treatment 3 times per day. The patients taking the kava supplements scored significantly lower on the Hamilton Anxiety Scale when compared to the placebo group (1).
-
A double-blind, placebo-controlled study involved 12 healthy young male subjects. The purpose of the study was to look at the affects of kava on memory. The results showed that those subjects taking kava had a better memory than the placebo group (2).
Cautions
-
Several German studies have linked kava to severe liver damage.The German Commission E recommends that if an individual taking kava experiences discoloration of the skin, nails, hair, enlarged pupils, and eye movement problems, kava should be discontinued and medical attention is warranted (3).
-
Those who are pregnant, breast-feeding, or diagnosed with Parkinson’s disease should not take kava.
-
Kava should not be taken along with alcohol, barbiturates, or other medications used to treat psychological disorders.
-
Kava should not be taken for periods longer than 3 months without physician’s permission.
-
An individual taking kava should not drive or operate heavy machinery.
-
In Australia, consumption of a kava beverage in large amounts (300 g to 400 g per week) has been linked to liver dysfunction, scaly skin, and poor health (4,5)
References
1. Kinzler E, Kromer J, Lehmann E. Effect of a special kava extract in patients with anxiety-tension and excitation states of nonpsychotic genesis. Double blind study with placebos over 4 weeks (in German). Arzneimittelforschung. 1991;41:584-588.
2. Munte TF, Heinze HJ, Matzke M, et al. Effects of oxazepam and an extract of kava roots (Piper methysticum) on event-related potentials in a word recognition task. Neuropsychobiology. 1993;27:46-53.
3. Blumenthal M, ed. The Complete German Commission E Monographs Therapeutic Guide to Herbal Medicines. 1st ed. Boston, Mass: Integrative Medicine Communications; 1998.
4. Mathews JD, Riley MD, Fejo L, et al. Effects of the heavy usage of kava on physical health: summary of a pilot survey in an Aboriginal community. Med J Aust. 1988;148:548-555.
5. Spillane PK, Fisher DA, Currie BJ. Neurological manifestations of kava intoxication. Med J Aust. 1997;167:172-173.