(Note: This week, Dr. Juan will be focusing on a serious disorder that affects a lot of people: anxiety. Here’s part one of his intriguing three-part series)
The upside of using the herbal cure kava to combat anxiety is that there is reasonably good evidence that it can work. The downside is that it may be not best to use the herbal cure due to its potential toxic effect on the liver. While the world’s kava experts continue to study the herb in an effort to make it safer for humans, let’s take a look at some of the research done on its influence on mood disorders.
Kava is a member of the pepper family used by Pacific Islanders to make a drink with ceremonial, medicinal and social uses. It has become a popular alternative treatment for insomnia and anxiety especially in Europe. Its active ingredients are chemicals known as “kavalactones” that affect neurotransmitter systems known to be involved with anxiety, including serotonin, glutamine, and dopamine.
Many clinical studies address kava’s effectiveness for anxiety disorders. The following four studies are of the highest quality:
1. In a study with 101 participants who had anxiety, they compared 90-100 mg of kava with placebo for 24 weeks. They found a significant decrease in anxiety among those treated with the herb. Side effects were the same in both groups.
2. Researchers tested 400 mg of kava per day with common antidepressants and anxiety medications in 129 people with generalized anxiety disorder. After two months, kava led to a similar reduction in anxiety as the drugs had.
3. A study tested 150 mg of kava a day vs. placebo in 141 patients with anxiety. Over four weeks, there was a significant decrease in anxiety for those on the herb. A side effect was increased tiredness.
4. In 391 people with anxiety and insomnia, researchers did not find that either kava or valerian relieved anxiety or insomnia better than placebo.
Overall, researchers have found kava extract an effective treatment for the symptoms of anxiety that is relatively safe for up to six months. Yet, the major safety concern is liver toxicity, including hepatitis, cirrhosis, and liver failure. There are at least over 100 reported cases of kava-related liver toxicity some requiring liver transplantation. For this reason, kava has been banned from the market in several countries such as Switzerland, Germany, the U.K., and Canada.
In the U.S., the Food and Drug Administration recommends that individuals with liver disease or who are using drug products that affect the liver seek medical advice prior to using kava. Moreover, kava users should be
alert to symptoms of serious liver disease (i.e. yellowing of the eyes or skin and brown urine) and seek immediate medical attention should these appear.
When you take kava, use non-root preparations. Don’t use it for longer than three months, don’t combine it with drugs or herbs that could have liver toxicity as a side effect, and don’t take doses higher than 300 mg a day.