Kava Safety Update

Six years after the widely publicized scare, is this herb safe to use?


| January/February 2008



kava leaf

Steven Foster

n December 2000, a 14-year-old American girl developed persistent nausea, vomiting, fatigue, weight loss and loss of appetite—a constellation of symptoms that suggested acute hepatitis. She saw a doctor, who prescribed rest and liver-function tests. The test results showed much more liver damage than hepatitis typically causes. The girl was hospitalized with liver failure and received an emergency liver transplant.

Liver failure is extremely rare in otherwise healthy teenagers. This girl did not use alcohol, which in large amounts is toxic to the liver, and she took no medications implicated in liver damage, just ibuprofen occasionally. However, she had taken kava (Piper methysticum) for 44 days to treat anxiety.

Alarming Reports from Around the World

This case was just one of approximately 82 reports from around the world of kava users developing liver disease ranging from mild impairment of liver function (elevated liver enzymes) to jaundice, hepatitis and even acute liver failure requiring a transplant in an estimated 12 patients. Nine of these people died.

By early 2001, these reports generated international headlines. USA Today: “Herb Kava Linked to Liver Problems.” The New York Times: “Questions About Kava’s Safety.” They also prompted several countries to ban the herb: Germany, Austria, Canada, France, Ireland, Singapore, Switzerland and the U.K. Kava was not banned in the United States, but the Food and Drug Administration (FDA) warned consumers about the possibility of life-threatening liver damage.

The Latest Research on Kava’s Benefits

The safety scare has pushed studies of kava’s benefits out of the news media. But research has continued—and it shows that kava is an effective treatment for anxiety and anxiety-related insomnia.

German researchers in 2003 compared kava (400 mg a day) with standard doses of two anti-anxiety medications in 129 people. After eight weeks, all three treatments were equally effective.

Other German scientists compared kava (100 mg three times a day) with standard doses of two drugs in the Valium family of tranquilizers in 172 people. After six weeks, all three treatments were equally effective.

A third group of German researchers gave 61 people with anxiety-related sleep problems either a placebo or kava (200 mg a day). Four weeks later, the kava group reported significantly more satisfying sleep.

Italian researchers gave one of three treatments to 68 women complaining of menopause-induced anxiety: a placebo, low-dose kava (100 mg a day) or high-dose kava (200 mg daily). Both kava treatments were significantly more effective than the placebo.

Two research teams, one British, the other German, performed sophisticated statistical tests (meta-analyses) on studies of kava for anxiety. The English group reviewed seven trials, the Germans six. In both analyses, kava proved an effective treatment for anxiety.

Kava sales plummeted—by 50 percent, according to one estimate published in Market Research Updates. As sales fell, so did reports of kava-induced liver damage. The controversy became old news—though not to herb researchers. Studies continued. Some studies made the herb look dirty for liver damage. Others made the safety scare look more like a tempest in a teapot—or in a traditional Polynesian kava bowl. In 2005, the German counterpart of the FDA repealed its kava ban. But soon after, the U.K. decided to uphold its ban on kava products.

Based on research to date, kava cannot be called completely safe. Like most pharmacologically active substances, it has benefits and risks. By the same token, it’s an overstatement to call this herb hazardous. The truth lies somewhere in between. Bottom line: Most people can use kava safely in recommended amounts. But kava consumers should be well informed about this herb because its downside—liver damage—though rare, is potentially life-threatening.





elderberry, echinacea, bee hive

MOTHER EARTH NEWS FAIR

Feb. 17-18, 2018
Belton, Texas

Sit in on dozens of practical workshops from the leading authorities on Natural Health, Organic Gardening, Real Food and more!

LEARN MORE