When all else fails, blame it on kava!
Unfortunately, says Yadhu Singh, professor of pharmaceutical sciences at South Dakota State University, that's what is happening in some countries around the world as more people are seeing their physicians for liver-related ailments.
The common denominator, according to many in the medical community, is kava, a popular pharmaceutical herbal supplement used successfully to treat stress, anxiety, restlessness, and insomnia.
However, after much discussion and research, including extensive analysis by Singh, he says there is convincing proof that kava is safe, although more research on the matter is warranted.
"There is no strong evidence that kava consumption in the traditional manner has severe adverse health effects," says Singh. "However, there is evidence to provide some concern about liver toxicity related to pharmaceutical kava preparations, although it is not sufficient to make firm conclusions."
The kava herb is derived from the kava plant, a robust, well-branching perennial shrub. It thrives at altitudes of between 150 to 300 feet above sea level and grows well in stony ground, both when cultivated and in the wild.
The plant can be found extensively on the islands of the Pacific Ocean, including Fiji, which is located northeast of Australia and north of New Zealand. It's the native home of Singh, who lived in the country for about thirty years and taught at the University of the South Pacific in Suva, Fiji.
Centuries of kava use
Singh was in Suva last November to attend the Pacific Kava Research Symposium "to clarify this whole situation," he says. "We were all mystified on why this (liver toxicity) was happening. It is of crucial importance there, because a lot of these countries depend on kava for economic reasons, mainly for exporting."
The traditional manner of consuming kava dates back many centuries. Kava acquired important symbolic meanings and with it came certain rules and procedures for its preparation, distribution among participants, and consumption.
Besides being the social beverage for chiefs and noblemen, it was also used to welcome distinguished visitors at formal gatherings. In time, it was used in almost all phases of life on the islands, including ceremonies, rituals, and religious activities.
Many medicinal purposes were reported as well. In Hawaii, for example, it was used to soothe the nerves, to induce relaxation, to counteract fatigue, and for congestion in the urinary tract, asthma, rheumatism, and weight reduction.
The traditional manner in making kava is to take the dried roots and lower stem of the plant and reduce them to fine particles. Water is poured into a large bowl containing the particles. The mixture is worked together, scooped up in a strainer and the infusion drained into the bowl, which is poured into a coconut shell cup for serving.
In the western world, instead of using pure water, organic solvents are utilized to extract the final kava product, which is then put into pill and other forms. Organic solvents are used because they extract larger amounts of kavalactones, the active ingredients, and the procedure is more efficient than water.
Contrasting methods
The two different ways of making kava have become the central focus of the kava investigation.
"We aren't sure if it's the method of extraction that is causing the toxicity," says Singh, who points out that the kava supplement has been banned in countries like Great Britain, Switzerland, and Germany. "Water only extracts those things that are soluble in water, but with organic solvents, there is a good possibility other substances that may be toxic are also extracted."
To verify that the water extraction process does not cause toxicity, since island inhabitants report no liver problems, Singh and Ashwini Devkota, a junior SDSU pharmacy student from Nepal, conducted a research project to prove the point.
"We evaluated the level of toxicity of kava on the liver function of young rats by measuring the effects on certain enzymes," explains Singh. "A significant increase in these enzymes would be considered an indication of liver toxicity."
After a few weeks of monitoring the animals, blood was obtained and serum prepared for enzyme analysis. The results showed there were no notable differences in the body weight and enzyme activity of the animals after two different dosage levels of kava.
"The data shows that kava did not produce any significant effects on the normal biological markers of liver toxicity," notes Singh, who indicates the research will now turn its attention to acetone extracts of kava. "Acetone is a very common organic solvent used to extract kava, so that's the next step in our research effort."
International conference slated
The symposium Singh attended voted to hold an international kava conference in November 2003. The meeting will include representatives involved in the medical, pharmaceutical, social, trade, and economic aspects of kava.
The conference will have two goals, according to Singh. One: consider multi-national clinical studies on the safety of traditional kava use in the community, and, two: collaborative laboratory research on toxicity of traditional kava extracts and kava-based pharmaceutical products.
"We want to provide a clear statement of the broad issues involved in the safety of kava use worldwide," he says. "How safe is kava when consumed both traditionally or as a pharmaceutical product? We hope to address these issues at the conference this fall."
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