Kava kava has a long and proven record of medicinal therapeutic value. This, however, has been stained by a few reports of liver toxicity. But the evidence shows quite the opposite. It shows that when Kava is taken properly, the risk to the liver is little, if even at all.
For example, in a large review of research from the University of Melbourne that included 24 clinical herbal studies, the researchers stated:
“Of the 435 clinical trial participants taking kava supplements in our review, some at high doses, no liver issues were reported. Therefore, the current review supports the conclusion that liver toxicity is indeed a rare side effect.”
The researchers also analyzed the “few” reports of Kava’s liver toxicity — the first of which was reported in 1998, well after many studies had been conducted – and stated:
“serious side effects may have occurred due to poor quality kava.”
Furthermore, researchers from Germany’s Goethe University of Frankfurt, the University of Melbourne and the Swinburne University of Technology in Australia have suggested that the reports of liver toxicity come not from ingesting Kava per se. Rather, they suggest that the evidence points to supplies of Kava that have become moldy.
They point to the type of liver toxicity that has resulted in the few cases of slight liver toxicity (mostly resulting in increased liver enzymes) actually being caused by fungal contamination of the Kava rather than the Kava roots themselves.
A paper from the University of Sydney’s School of Pharmacy also revealed this possibility. While they weren’t convinced they did admit that, “background levels of aflatoxin have been detected in kava samples.”
The proposal — based on a thorough examination of the cases of Kava-liver issues as well as new research showing a lack of liver toxicity from properly prepared Kava — completely makes sense.
Why? Because for most of the history of the Kava industry, Kava has been harvested and prepared by native populations among Pacific Islands where the plant is indigenous. The roots are often harvested in bulk and then stored in an exposed facility until preparation. As such, the handling and preparation of the dried Kava powder may easily become subjected to mold or any number of other contaminants as the roots are stored awaiting processing.
A lack of manufacturing protocols in Kava production in the past has thus been largely been left to native harvesting groups, because this was the major source of Kava. Market buyers were in no position to begin dictating protocols.
Increasingly, many Kava suppliers harvest and process their Kava using international manufacturing standards such as ISO, GMP and others. Because of the restrictions by first world countries now on the importation of raw ingredients, these protocols are now stricter. Still, it often depends upon the particular importer of the product — whether or not they inspect and demand adherence to good manufacturing practices.
Another study — which analyzed the components of Kava kava, found there to be no compound in the Kava that should cause liver toxicity. They concluded:
“To date, there remains no indisputable reason for the increased prevalence of kava-induced hepatotoxicity in Western countries.”
Other evidence shows that in many of the reports of liver toxicity, alcohol consumption was involved and in some cases, pharmaceuticals that affect the liver were also involved. These of course include acetaminophen and many other over the counter drugs. After a review of most of the Kava liver toxicity cases (a little over 100), the researchers concluded:
“Alcohol is often co-injested in kava hepatotoxicity cases.”
In other words, there is enough evidence — the lack of toxicity among clinical studies, the potential for mold and other contamination of Kava root, and the ingestion of Kava with alcohol and/or other drugs — to make a case that the risk of liver toxicity from pure Kava when there is no alcohol or drugs consumed is minimal. And most of us know that both alcohol and many OTC drugs damage the liver. In fact, there are tens of thousands of liver toxicity cases every year in the U.S. alone.
As to the use of Kava as an herbal medicine, its therapeutic value remains irrefutable.
Let’s review some of the medicinal uses of Kava, according to the research:
Kava relieves anxiety
A number of human clinical studies have shown that Kava relieves anxiety. In a review of the research from the University of Melbourne, four of six human clinical studies conducted with Kava for anxiety showed that:
“The current weight of evidence supports the use of kava in treatment of anxiety with a significant result…”
A more pervasive review from California’s Global Neuroscience Initiative Foundation — this involving 24 studies of Kava and other herbal medicines for anxiety, found that there was substantial evidence that Kava relieved not only anxiety, but also restlessness and insomnia. They also looked at animal studies that showed that Kava has anxiolytic effects “but not sedative or mental impairing” effects “which are typical side effects caused by benzodiazepines.”
Kava extracts have also been seen to bind to GABA and dopamine receptors, as well as opiate receptors.
In one of these studies 101 adults were given either Kava or a placebo for 25 weeks. The Kava group showed significant improvement in “primary and secondary anxiety symptoms.”
Primary anxiety relates to long term stress and anxiety (since childhood) while secondary anxiety relates to clinical disorders.
Five other randomized controlled clinical trials and one observational study supported these results. They supported Kava as a potential “monotherapy” (meaning no other medications give) or for those who were coming off of benzodiazepines.
The researchers noted that Kava’s use with St. John’s wort has not been productive.
Kava also relieves depression
Other studies have showed Kava has antidepressant effects. A three-week study from The University of Queensland gave 60 adults 250 milligrams kavalactones per day or a placebo. At the end of the three weeks, the Kava group had significantly lower levels of depression compared to the placebo group, using Montgomery-Asberg Depression Rating Scale scores.
The researchers concluded:
“The aqueous Kava preparation produced significant anxiolytic and antidepressant activity and raised no safety concerns at the dose and duration studied.”
They also added:
“The aqueous extract was found to be safe, with no serious adverse effects and no
clinical hepatotoxicity [liver toxicity.”
Other studies have supported Kava’s antidepressant effects.
Kava improves mood issues during menopause
A study from the University of Illinois Medical School found that Kava can significantly reduce mood-related anxiety during menopause.
Kava improves cognition
Okay, so Kava relaxes the muscles and the mind. But doesn’t it affect cognition the way other antidepressants and anti-anxiety drugs do? Certainly, as some researchers have pointed out among Kava-takers — the tendency to “sway” when on Kava.
Despite this effect, there is clear evidence that Kava actually has the opposite effect — it can boost cognition and attention.
After a review of 10 clinical studies of Kava, researchers from Australia’s Brain Sciences Institute at Melbourne’s University of Technology found that Kava did not affect cognition negatively whatsoever. In fact, in some studies, Kava: “significantly improved visual attention and working memory processes.”
The researchers stated that Kava’s “enhanced cognition may be attributed to the ability of kava to inhibit re-uptake of noradrenaline in the pre-frontal cortex…”
In a study from the University of Melbourne that compared Kava to oxazepam, it was found that Kava did not negatively affect cognition the way the oxazepam did. They stated:
“Kava was found to have no negative effect on cognition, whereas a reduction in alertness occurred in the oxazepam [group].”
Kava prevents and may even treat several types of cancer
Other research has learned that certain Kava components, such as Flavokawain B, reduce tumor growth and inhibit cancer.
A study from the University of California at Irvine illustrated that these Kava components kill and inhibit prostate cancer tumors.
A study from the University of Minnesota found that methysticin from Kava significantly inhibited NF-kappaB activation, therapy halting lung tumor growth.
Another study showed Kava compounds suppressed TNF-alpha among cancer cells.
Yet another study from the University of California/Irvine showed flavokawain A inhibited the growth of bladder cancer cells. The researchers concluded:
“This selectivity of flavokawain A for inducing a G(2)-M arrest in p53-defective cells deserves further investigation as a new mechanism for the prevention and treatment of bladder cancer.”
Kava kava constituents
Kava’s central anti-anxiety constituents are kavalactones. In fact, this is why most kava is now standardized to kavalactone content. Constituents mentioned above include flavokawains and methysticin. Others include kawain, yangonin, dihydrokavain, desmethoxyyangonin, and dihydromethysticin. These all have different neurological effects, including MAO-B inhibition in the case of desmethoxyyangonin. Kawain’s effects are sedative and tranquilizing, as well as anti-convulsant according to the literature.
The bottom line: Kava provides one of the best proven herbal medications to treat anxiety and depression. It also aids cognition and some of its constituents may prevent and even treat different cancers.
Utilizing Kava safely can be accomplished with a few simple measures:
1) Choose a reputable brand known for its focus on quality control.
2) Choose a product that has been standardized to kavalactones.
3) Extracts are best because of their quality control. Non-alcohol liquid extracts are available.
4) Take only the amount as recommended by the manufacturer.
5) Take a day or two off for every few days used. (Don’t take everyday).
6) Do not consume alcohol or take any medications with Kava.
7) Do not consume Kava with other herbal medications.
8) Don’t drive after you take Kava.
9) If you have sensitive skin, consider staying out of the sun after consuming Kava, as it has been known to cause photosensitivity among sensitive people — as do other herbs such as St. Johns Wort.
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