Dear Kava Guru,
Can Kava really cause liver damage?
Linda, Carson City, CA
To answer your question simply – there hasn’t been any formal or concrete evidence to indicate that pure kava kava causes liver damage or toxicity. In fact, South Pacific Island populations have been using kava kava (Piper Methysticum) for centuries on end without any known incidences of liver damage .
Now for lengthier Kava Guru wisdom on the topic of liver damage:
Kava kava has effects that are said to be similar to those felt from the consumption of alcohol – alleviation of stress, mood elevation, contentment, and overall relaxation. Kavalactones, the kava compounds believed to grace us with those benefits, have been shown to have anesthetic and muscle relaxation effects as well . Given these much sought-after qualities, it’s no wonder it has been used as a remedy for anxiety, insomnia and other neurological disorders and is steadily growing in popularity!
Additionally, kava kava has been shown to actually improve cognitive functioning, making it a worthy alternative to other neurological medications that impair cognitive functionality. For instance, the University of Maryland Medical Center recently published an article that documents a 2004 case study. This case suggests that 300mg of kava kava can actually improve cognitive functioning while alleviating anxiety. As the article also indicates, this is quite a significant result given that standard anti-anxiety medications, like diazepam (Valium), have been proven to cause cognitive impairment .
This information could substantiate the reasoning behind the recent evidence that pharmaceutical giants have conducted false and corrupt reports about kava kava and liver damage, in order to have them banned from hosting countries. Given that kava kava has become an increasingly popular anti-anxiety, and insomnia remedy, with the added benefit of cognitive improvement – it’s no wonder that some may think that pharmaceutical companies might have a vested economic interest in devaluing kava kava.
Not to mention that there are even reports about “fake kava” being distributed that are actually chemical elixirs intended to induce a “high” and have nothing to do with kava at all! These elixirs are reported to cause some pretty serious health risks due to the types of toxic chemicals used in their preparation and these cases have been lumped in along with other information regarding kava – and it’s not even kava! Inevitably these types of cases end up in skewed and misinformed data regarding kava.
According to LiverTox and the World Journal of Gastroenterology, there are some documented cases indicating that some individuals have had liver damage and in a few cases required liver transplants after using kava kava [2,3]. However, several other sources, including the American Association of Family Pharmacists (AAFP) and the Journal of Toxicology have indicated that there is no evidence of permanent liver damage . Additionally, Yadhu Singh – an author that writes extensively on the subject of Kava – states that these problems were not encountered with the traditionally prepared beverage, which was prepared as a water infusion. Commercialized Kava extracts, that are extracted with organic solvents, are the source of Kava used in the potential cases of liver toxicity . Further yet, a professor out of Menzies University – Medical School has studied aboriginal populations of Australian Northern Territories, who were first introduced to kava kava as an alternative to drinking alcohol in the 1980’s, and there were no records of hepatotoxicity related to kava kava during those studies. And interestingly enough, the subjects of these particular cases ingested a substantially larger amount of kava kava (10-50 times) than what is recommended by European standards .
However, the same studies do address a temporary change in liver functionality. This change in liver function – namely, fluctuations in the liver enzymes gamma-glutamyl transferase and alkaline phosphatase  – may allow for some understanding about the misrepresentation of kava kava with regard to liver damage. Furthermore, it is important to note that changes that do occur from using kava kava, are temporary – that is, liver functions become normal after a short period of time after using kava kava. Additionally, there is some indication that kava kava ingestion could disable certain enzymes, such as cytochrome P450 and cyclooxygenase . It is possible that due to the change in liver function, enzymes normally used in the metabolizing of ethanol and other substances may not properly function during the short period of time that kava kava is in the system. As a result, consumption of alcohol or drugs while taking kava kava could result in liver toxicity. It is possible that the subjects of documented liver damage cases had a history of alcohol or drug abuse, and that they either had damaged livers prior to the case studies or that they were actively using other substances during the studies. This toxicity then is not necessarily due to kava kava itself, but is more likely due to the misuse of kava kava with other substances. It would be wise then to not use kava kava with other substances, and this recommendation does not differ from the solo-usage requirements of other medicinal remedies [6,7].
There is also a body of evidence indicating that cases of kava kava liver damage or toxicity, if any, are due to an improper usage of the plant itself. The AAFP suggests that cases of liver damage may arise from use of parts of the plant other than the root. The leaves, stem and other aerial parts of kava kava that are not directly derived from the root, do come up in some bodies of evidence as poisonous or toxic. Additionally, there is evidence to suggest that the kava extracts, used by the subjects in many of the cases of liver damage, could have been impure (tainted with other substances). Many commercial kava kava extracts contain as much as %60 ethanol, and are labeled as “standardized” simply on the basis that they contain a prerequisite amount of a given substance (in this case, kava kava) . This suggests poor-quality and/or contaminated kava kava raw material, as a possible explanation for toxicity – not pure kava kava derived only from the plant’s roots [5,6,7].
In his discussion of prospective considerations with regard to hepatotoxicity (liver toxicity) due to kava kava, Rolf Teschke thoroughly addresses all of the above reasons for the misinformation surrounding kava kava. Teschke indicates that in the cases where liver damage has been linked to kava kava, there was evidence of co-medication and improper adherence to dosage recommendations. He furthermore addresses the possibility that the incorrect, and toxic, parts of the plant were used in those studies. “By improving kava quality [purity] and adherence to therapy recommendation under avoidance of co-medication, liver injury by kava should be a preventable disease…” (Teschke, p. 1270).
Furthermore, the Journal of Toxicology not only indicates that there have been no cases of liver damage directly and undeniably linked to kava kava, but also that there is no evidence of liver toxicity or damage in Pacific Island populations – populations that have traditionally and properly been using kava kava for centuries .
Also, like with pretty much anything, overly high dosages are likely to play a factor in cases of toxicity. If you take too much kava kava, no matter the source – there are likely to be negative consequences. It’s probably similar to how a glass of red wine a day has been proven to alleviate stress and be beneficial in other ways – and yet, as we all know, too much alcohol can be quite damaging to our livers!
Kava Guru thinks it breaks down to this: anything in large quantities, or used incorrectly, is going to reap unhealthy results. Sources suggest that small to moderate dosages of pure kava kava root – not the stem or leaf – do have benefits and are a solid alternative to pharmaceutical methods for alleviation of anxiety, insomnia, pain and other neurological problems.
And if you take nothing else away from reading this, do remember the following three bits of wisdom:
1) Do not combine kava kava with drugs or alcohol. Like with most – if not all – other medicinal substances this can not only interfere with the benefit of kava kava, but could also cause liver damage (as stated in more detail above).
2) Moderate and monitor your use! If your intended use is for a longer duration of time – such as for medicinal purposes – then do ensure that you seek out a physician specialized in medicinal plants for advice on dosage amounts and duration.
3) And, as any guru of any product would remind you – always do your research on the vendor! Only buy kava kava from those companies that give you a guarantee that their product is pure kava kava made strictly from the root of the plant. If they cannot vouch for their purity, that’s probably an assurance that the product is not pure.
If you follow those three points of wisdom, you will be sure to revel in the benefits of kava kava – a comfort that has been quietly enjoyed by the traditional people of the South Pacific islands for many upon many blissfully peaceful centuries.
Keith @ Kava Guru
1. Cassileth, Barrie, PHD. “Oncology”. United Business Media LLC, San Francisco: April 15, 2011. Vol. 25-4 p. 384-385.
2. Clough AR, Bailie RS, Currie B. “Liver function test abnormalities in users of aqueous kava extracts”. Journal of Toxicology. 2003. 41(6):821-9. http://www.ncbi.nlm.nih.gov/pubmed/14677792
3. Fu S, Korkmaz E, Braet F, Ngo Q, Ramzan I. “Influence of Kavain on Hepatic Ultrastructure”. World Journal of Gastroenterol. January 28, 2008: 14(4): 541-546. http://www.sciencedaily.com/releases/2008/02/080222111446.htm
4. Singh, N. Yadhu. “Potential for Interaction of Kava and St. John’s Wort with Drugs”. Journal of Ethnopharmacology, 2005. Vol 100, p. 108-113.
5. Saeed, Bloch, and Diana Antonocci. “Herbal and Dietary Supplements for Treatment of Anxiety Disorders”. Association of American Family Physicians, Aug 15, 2007: 76(4) p. 549-556. http://www.aafp.org/afp/2007/0815/p549.html
6. Teschke, Rolf, MD. “Kava Hepatotoxicity: pathogenetic aspects and prospective considerations”. Liver International: October, 2010. Vol. 30-9, p. 1270-1279.
7. University of Maryland Medical Center. “Kava Kava”. Last modified: May 07, 2013. http://umm.edu/health/medical/altmed/herb/kava-kava
8. U.S. National Library of Medicine. “Kava Kava – Piper Methysticum”. Last modified: March 03, 2014. www.livertox.nlm.nih.gov/KavaKava.htm
9. Whitton, Lau, Salisbury, Whitehouse and Christine S. Evans. “Kava Lactones and the Kava-Kava Controversy”. Pergamon: June 5, 2003. Phytochemistry (64) p. 673-679.
10. Wikipedia. “Kava-Toxicity and Safety”. Last modified: February 21, 2014. http://en.wikipedia.org/wiki/Kava#Toxicity_and_safety