What causes the weird effects of kava?

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Those who have an eye on the fast-paced world of recreational pharmacology will probably have heard of kava. Kava (or kava-kava) is a plant, long known in the South Pacific, that induces a sense of relaxation. It also induces euphoria. And helps you diet. And acts as an effective anesthetic. How does it manage all this? Find out!

If you are in America and go to a sufficiently hippie-inspired store you will probably find a wall full of "relaxation" teas. Most of those teas are of no more worth, when it comes to relaxation, than a regular cup of hot water. However, one might help you out a little bit. That would be "kava" or "kava-kava" tea. They may not be high quality, but the plant they contain is one of the better-known legal drugs.

Kava is a plant found widely throughout the Pacific islands. Its use varies, from island to island. In some places it is part of a solemn ceremony. In others it's consumed in the equivalent of bars. Wherever it is consumed, it is pounded, ground up, or chewed, and then soaked in water. People then drink the water by the bowlful over the course of an evening, and, given its effects, it's not surprising to see why. While kava's taste is described as both bitter and "dirt-like," it gives the drinker a sense of calm and relaxation, and sometimes a sense of euphoria. It also has a host of other effects, one of which is bitterly disputed.


Kava, once gulped down, goes to work on the body via about fifteen different compounds, known as kavalactones. These different compounds are present in different amounts, depending on the exact strain of kava, but the ones that are responsible for kava's popularity are known as kavain and desmethoxyyangonin. Kavain induces a feeling of relaxation, like a sedative. Unlike a sedative, it doesn't do so by knocking out the brain. Instead it's a muscle relaxant, physically relaxing the body and letting the brain follow along. This leaves kava drinkers relaxed but alert. Desmethyoxyyangonin, meanwhile, increases dopamine in the brain, giving people a mild euphoric sensation. (Another kavalactone, yangonin, works the same brain channel as THC, and also contributes to the good feelings that people have while on kava.)


Kavain has a less-pleasant effect. It's a topical anesthetic that numbs on contact. People gargle with kava for tooth aches, but mostly it's a source of embarrassment for people who haven't tasted kava before and attempt to talk after their first bowl. With their numbed mouths they like they've just had dental surgery. Kava consumed before a big meal might be a real problem, but few people feel like eating after kava. There's a reason why most topical anesthetics aren't swallowed. Kavain keeps numbing as it moves through the body, and people who swallow can experience extreme nausea as the anesthetic goes to work on their stomach. Habitual kava drinkers lose the nausea, eventually, but the numbing agent still works. Kava suppresses the appetite.

With all these effects - euphoria, relaxation, and appetite suppression - one would think that kava use would be much more widespread than it is. There's a reason no one drinks a kava-n-kale smoothie to slim down. In the early 2000s, heavy kava drinkers in Europe and America started having liver problems. A study linked kava to liver damage and a few fatal poisonings. The drug dropped out of sight most places, and was banned entirely in Germany, Switzerland, and Canada. But does kava destroy the liver?


Like many scientific questions, there isn't a definitive answer. Over the next few years, some researchers have poked holes in the original paper. Other studies, done on kava drinkers in the south Pacific, have noted that they don't suffer from liver damage any more than any other population. Some speculate that certain kava exporters weren't careful to only include the roots of the plant, and were grinding the toxic leaves and stems of the kava plant into their powders to increase the weight.

Today, kava seems to be making a comeback. It's possible that kava drinkers are more careful. It's possible that the health scare was unsubstantiated. And it's possible that the idea of getting high without getting the munchies might be more valuable than a liver.


Via The Quality of Kava Consumed in the South Pacific, NCBI, 1 Hour Break.