Kava is a plant that has been used for centuries in the South Pacific as part of traditional rituals and ceremonies.
Recently, kava has garnered attention from the medical community for its potential therapeutic benefits, particularly as an anti-anxiety treatment and possibly even for cancer prevention and treatment.
Key facts about kava:
- Kava is made from the roots and rhizomes of the Piper methysticum plant. It has been consumed in the Pacific Islands for 3000+ years.
- The active ingredients in kava are kavalactones, which have psychoactive and potentially therapeutic effects.
- Kava has been shown to have anti-anxiety and relaxant properties and is used to treat anxiety, insomnia, and menopause symptoms.
- Some research indicates kava may have anticancer and chemopreventive potential, but more studies are needed.
- There are concerns about potential liver toxicity with long-term high dose kava use. Guidelines have been developed to minimize risk.
Source: J Clin Med 2022
Kava: A Millennia-Old Ritual Drink
Kava is a traditional drink of the South Pacific that has been used for 3000+ years in cultural rituals and medicinal practices.
The name comes from the Polynesian word “ava” or “kava”, meaning bitter.
Kava is made by grinding up the root and rhizomes of the Piper methysticum plant and mixing the powder with water or coconut milk to create a bitter, muddy brew.
Kava preparation and consumption were traditionally exclusive to men and served ceremonial purposes, often marking milestones like births, deaths, and arrivals of chieftains.
Kava was also used medicinally to treat various ailments.
While kava is still important culturally today, consumption has expanded beyond ritual uses into casual social gatherings.
Women are also now participating in kava drinking.
The psychoactive properties of kava come from a class of compounds in the plant called kavalactones.
The highest concentrations are found in the roots.
6 major kavalactones make up about 96% of kava’s effects: methysticin, dihydromethysticin, kavain, dihydrokavain, yangonin, and desmethoxyyangonin.
Researchers think kavalactones produce kava’s relaxing, euphoric sensations by interacting with the brain’s GABA receptors and dopamine pathways.
Kava for Stress & Anxiety Treatment
In the 1990s, kava began to attract attention in Western medicine for its potential as a natural anxiety treatment.
Numerous studies have shown kava is effective in reducing anxiety, comparable to prescription medications like benzodiazepines.
A recent review found it outperformed placebos in 3 out of 7 clinical trials.
The kavalactones appear to have anxiolytic effects by binding to GABA-A receptors and blocking norepinephrine reuptake.
Besides anxiety, kava has been studied for insomnia, ADHD, depression, menopause symptoms, chronic pain, and epilepsy.
Small studies suggest it could be useful but more research is needed.
Currently kava is approved in Europe for anxiety treatment and by the FDA as a dietary supplement.
Dosage guidelines recommend using only standardized root extracts and limiting intake to under 250mg kavalactones per day, for no more than 3 months.
While kava does not appear addictive or impair cognition at therapeutic dosages, there are safety concerns with long-term high-dose use.
The biggest risk is potential liver toxicity, which has led to kava bans in the past.
Guidelines have been introduced to minimize this risk.
Kava Safety Concerns & Risks: Hepatotoxicity & Liver Failure
In the early 2000s, reports of liver damage and liver failure in kava users led to bans in Europe and strict warnings from the FDA.
However, most cases involved very high doses taken for prolonged periods of time.
Analyses suggest liver risks are substantially lower for water-extracted roots at dosages under 250mg kavalactones per day.
The exact mechanisms behind kava hepatotoxicity are unclear but could involve metabolism-related interactions or toxicity from non-root plant parts.
Certain extraction methods, contaminants like mold, and co-consumption of alcohol or drugs may also increase risks.
Individual genetic differences in metabolizing kavalactones likely play a role as well.
To minimize potential liver injury, current guidelines recommend:
- Using only peeled root/rhizome extracts
- Avoiding stem peelings and leaves which contain toxic alkaloids
- Limiting dose to <250mg kavalactones per day
- Taking for no longer than 3 months continuously
- Avoiding combination with alcohol, drugs, or herbs with hepatic effects
- Avoiding use in those with liver problems or taking hepatotoxic medications
Other side effects like headache, dizziness, and stomach upset are generally mild.
While a few case reports link kava to liver damage, uncontrolled cases do not prove causality.
Overall kava appears relatively safe when used properly and short-term.
Kava & Cancer: Possible Anticancer Effects?
While kava is garnering interest for its therapeutic potential in anxiety and other areas, some research also hints it may have anticancer properties.
This is an emerging area needing much more study but initial findings are intriguing.
Population studies show lower cancer rates in groups with high kava consumption like Pacific Islanders.
Animal and lab studies demonstrate kava extracts and compounds like flavokavains and kavalactones can inhibit growth, induce apoptosis, and prevent metastasis in certain cancer cell types.
Human pilot studies also show anticancer effects of kava compounds on cancer biomarkers.
Proposed mechanisms include cell cycle/proliferation disruption, apoptosis activation, blocking carcinogen metabolism, anti-inflammatory effects, and more.
Kava constituents appear most promising against lung, prostate, bladder, breast, gastric, and colorectal cancers.
However, kava is classified by the International Agency for Research on Cancer as a possible carcinogen based on liver tumors seen in animal studies.
The relevance of this animal data to humans is debated and thought to involve non-genotoxic mechanisms.
But more research is still needed on kava’s seemingly contradictory carcinogenic yet anti-carcinogenic effects.
Overall, kava shows preliminary anticancer potential but human evidence is extremely limited.
Well-designed clinical trials are necessary to clarify if kava or its components could be developed into novel cancer chemoprevention or chemotherapy agents.
Any anticancer application would also need to be carefully weighed against potential long-term toxicity risks.
Conclusion: Kava is a Promising yet Precarious Plant
Kava is an ancient plant that continues providing cultural value and potentially health benefits into the modern era.
When used properly, it appears relatively safe and shows promise in treating anxiety and possibly other conditions.
Standardization and regulation to ensure quality extracts and dosing are important.
While severe liver toxicity is a valid concern needing further study, guidelines can minimize risks.
Kava’s preliminary anticancer effects are also exciting but require substantial additional research.
This traditional South Pacific brew is complex – it has demonstrated therapeutic potential but, like many plant medicines, also comes with risks.
With thoughtful science and application, kava may one day find an appropriate place in integrative medicine.
But it remains a precarious plant requiring prudent use and further investigation.
References
- Study: An updated review on the psychoactive, toxic and anticancer properties of kava
- Authors: Rita B. Soares et al. (2022)
