Physiological Effects of Kava
Fresh kava rootstock, when prepared by mastication, pounding, or grinding, yields a greenish milky potion that is considerably stronger than the grayer mixture obtained from dry roots. Before L. Lewin began his scientific research on the plant in Germany during the nineteenth century, it was generally believed that the method of preparation was the only factor that determined the strength and kind of kava’s physiological effects. It was assumed that saliva, mixed in during the mastication process, converted starches contained in kava rootstock into sugar, which produced alcohol when fermented. Lewin (1886a) concluded more than a century ago that “this theory is incorrect in every respect.”
Steinmetz (1960) was the first to point out that the main factor determining the psychoactive impact of kava is the degree of separation in water of the resinous active ingredients. Van Veen (1939) had noted that for kava to be most effective, rootstock must be emulsified very finely in water, saliva, lecithin, or oil to disperse the active ingredients. Mastication transforms rootstock mass into tiny particles, releasing the resin stored in the cell tissues. The active substances in this resin, insoluble in water, become available to the drinker after emulsification. This, rather than the action of saliva, explains why kava drink prepared by grinding or pounding rootstock often has less physiological effect than that produced from finely chewed, emulsified rootstock.
Infused kava is an emulsion of lipidlike compounds suspended in water. The resinous compounds present in each cell of the rootstock as microscopic drops are dispersed when the root tissues are macerated and infused. When the beverage is ingested, thousands of these microscopic particles transit rapidly through the stomach membrane to the bloodstream. If the emulsion is rich in active resinous compounds, this will induce a rapid and pronounced psychoactive effect.
Of all the scientists who have studied the physiological effects experienced by kava drinkers, Lewin has provided some of the most eloquent descriptions. In 1886 he noted that “a well-prepared kava potion drunk in small quantities produces only pleasant changes in behavior. It is therefore a slightly stimulating drink which helps relieve great fatigue. It relaxes the body after strenuous efforts, clarifies the mind and sharpens the mental faculties. If a certain quantity of these active elements is absorbed they produce special narcotic effects” (Lewin 1886a). A later publication (Lewin 1927) offers a more detailed description of kava’s effects on the human mind and body:
When the mixture is not too strong, the subject attains a state of happy unconcern, well-being and contentment, free of physical or psychological excitement. At the beginning conversation comes in a gentle, easy flow and hearing and sight are honed, becoming able to perceive subtle shades of sound and vision. Kava soothes temperaments. The drinker never becomes angry, unpleasant, quarrelsome or noisy, as happens with alcohol. Both natives and whites consider kava as a means of easing moral discomfort. The drinker remains master of his conscience and his reason. When consumption is excessive, however, the limbs become tired, the muscles seem no longer to respond to the orders and control of the mind, walking becomes slow and unsteady and the drinker looks partly inebriated. He feels the need to lie down. The eyes see the objects present, but cannot or do not want to identify them accurately. The ears also perceive sounds without being able or wanting to realize what they hear. Little by little, objects become vaguer and vaguer. The drinker is prey to exhaustion and feels the need to sleep more than any other sensation. He is overcome by somnolence and finally drifts off to sleep. His sleep is similar to that induced by alcoholic inebriation and the subject comes out of it grudgingly. When the mixture is of moderate strength the effect is felt twenty to thirty minutes following its absorption. The effect lasts for about two hours, sometimes longer and up to eight hours. How long the effect lasts depends on the drinker’s level of inurement. When the mixture is concentrated, i.e., when it contains a lot of resinous elements, the effect is felt much more quickly. Drinkers can be found prostrate at the place where they have drunk their kava. Before falling asleep, they could have suffered slight nervous trembling. During their sleep, sensitivity is reduced. No excitement precedes these symptoms. (Translation by R. M. Benyon in Lebot and Cabalion 1988)
A more recent but equally graphic description of kava’s effects is provided by Gregory, who writes from his own experience with the drug:
Kava seizes one’s mind. This is not a literal seizure, but something does change in the processes by which information enters, is retrieved, or leads to actions as a result. Thinking is certainly affected by the kava experience, but not in the same ways as are found from caffeine, nicotine, alcohol, or marijuana. I would personally characterize the changes I experienced as going from lineal processing of information to a greater sense of “being” and contentment with being. Memory seemed to be enhanced, whereas restriction of data inputs was strongly desired, especially with regard to disturbances of light, movements, noise and so on. Peace and quiet were very important to maintain the inner sense of serenity. My senses seemed to be unusually sharpened, so that even whispers seemed to be loud while loud noises were extremely unpleasant. (Gregory and Cawte 1988)
