Some time ago when kava became better known on the wild, wild interweb and scientists began investigating its applications, a popular meme has spread about kava having a link to liver damage.
Considering that kava is an excellent anxiolytic substance1 indulged in tradition by some Pacific Island cultures much in the way we use alcohol in the West, it has to be too good to be true. Does it really cause liver damage? Do you have to carefully moderate your use of the kava root to protect yourself?
As I write this, I am enjoying more of the instant kava I had last week. In addition to my daily use of it in that previous week, I’ve used it more since then and I’ve taken a couple days off from it without any consequence. So far, so good. But what of those myths, is there any truth behind them?
Rarity of liver toxicity from Kava Root
According to a 2015 report2 (behind a paywall unfortunately), any supposed link between kava and liver toxicity is tenuous and rare at best.
Despite the link to kava and liver toxicity demonstrated in vivo and in vitro, in the history of Western kava use, toxicity is still considered relatively rare. Only a fraction of the handful of cases reviewed for liver toxicity could be, with any certainty, linked to kava consumption and most of those involved the coingestion of other medications/supplements. That means that the incident rate of liver toxicity due to kava is one in 60-125 million patients.3
The connection was so tenuous, that Germany, a country who banned kava almost on kneejerk response to the purported liver connection in 2002 that they recanted their ban recently4 after new findings discovered that kava should be okay, at least if your kava source is okay.
The American FDA on the other hand have not rescinded or updated their liver health advisory on kava since it was released in 2002.5 Perhaps this is for good reason as it is possible that some unscrupulous supplement sellers may try to shill stem and leaves which is a very bad thing as we will see soon.
Kava and mycotoxins, or: why haven’t the Pacific Islanders suffered liver damage from Kava?
It’s been called the “Kava paradox.” Only people in the West have suffered liver problems allegedly due to kava use, whereas the Pacific Islanders have had no issue. This problem has been attacked from different angles, including preparation, the parts of the plant used, genes, and more.
A 2012 study noted that the cases of liver damage were limited to Western products featuring an extract of kava, suggesting mycotoxin.6
It appears that the primary cause of toxicity may reside in the time before the preparation of the various kava extracts, possibly attributed to poor quality of the raw material caused by mould hepatotoxins. Rigorous testing of kava raw material is urgently advised, in addition to Pan-Pacific kava manufacturing quality standards.
If the mycotoxin case is true, we would need to learn who has the best products, and which ones test theirs for purity. Ideally one would find a seller that makes their third party lab purity tests publicly available for customers to view, but this is not always possible.
As your humble guinea pig/author, the Kava King branded product I reviewed in my previous article has not caused me any problems, nor the previous Gaia Herbs tincture that I’ve tried in the past, but I am unsure of their purity as of this writing. If you are on the hunt for kava, ask your chosen vendor for a copy of their purity or lab testing. Any seller worth their salt will have one.
Kava Root Vs. Kava Stems and Leaves
Traditionally, the Pacific Islanders who indulge in kava do not use the stems and leaves in their preparation of the drink, and this is for a very good reason.
Instead they use only the roots and make it into a cold water extract. They did not extract it with alcohol or any other solvent.
One of the more toxic constituents of kava, pipermethystine7 , appears in concentrations of up to 2000 parts per million in the leaves of the kava plant, but appears in medical kava root extracts at concentrations of less than 45 ppm.8 The root if it has any at all, has negligible concentrations of this substance.
When you get your kava, make sure that it does not contain stems or leaves.
Recap: Which Kava Products are Best?
- Although it’s relatively high priced, Herb Pharm’s kava tincture is not made with stems and leaves, only the rhizome and root of the mature plants.
- See also: Gaia Herbs Kava Tincture and Gaia Herbs Kava Liquid Veg Capsules
- Kava King, based on their website, uses only the root in their instant kava powder mix.
- You can prepare kava the traditional way by purchasing kava root powder or whole roots and using these instructions from Erowid.org. See also this contributor’s guide.
It appears that kava kava is safe based on centuries of traditional use by Pacific Islanders. With a sample size that large, you’d have to be a fool to draw any other conclusion. The liver damage scare may not have been wholly unwarranted seeing as the leaves and stems of the kava plant contain a toxic compound, but not found in the root which the kava drink and the quality modern extracts are prepared.
You should consult with your doctor about your liver condition before having any kava, and you should always make sure your source is selling you a quality product free of contaminants, stems or leaves. With all that said, it’s a great substance.
PubMed — Kava extract for treating anxiety. ↩
PubMed — Contemporary Pacific and Western perspectives on `awa (Piper methysticum) toxicology. [Paywall for full text] ↩
Wikipedia — Kava – Toxicity and Safety ↩
Pacific Islands Report — Germany Officially Ends 15-Year Kava Ban ↩
FDA.gov — Safety Alerts for Human Medical Products > Kava (Piper methysticum) ↩
PubMed — Kava hepatotoxicity in traditional and modern use: the presumed Pacific kava paradox hypothesis revisited. ↩
Wikipedia — Pipermethystine ↩
PubMed — Is the alkaloid pipermethystine connected with the claimed liver toxicity of Kava products? ↩