Kava drinking increases liver GGT levels

The Honolulu Advertiser had an article in the paper this morning about how Kava drinking creates a "liver anomaly."

"There's some evidence of something happening in the liver," said Dr. Janet Onopa, an assistant professor of medicine at the John A. Burns School of Medicine who analyzed the data and reviewed the lab reports. "But it doesn't seem like anything catastrophic."
....
The blood work revealed elevated levels of the liver enzyme GGT — or gamma-glutamyl transpeptidase — in 65 percent of the kava drinkers. The levels of GGT increased with increased kava consumption.
In the control group, high GGT levels were only seen in 26 percent of the non-drinkers.
"We don't know exactly what a high GGT in and of itself means," Onopa said. "It's possible that kava just induced that enzyme without doing any liver damage."

Kava is a traditional drink of Samoa and Fiji. The active ingredient, kavalactone, comes from the root of the plant Piper methysticum. It causes numbing of the lips and tongue when consumed and a mild intoxication of calming quality. Some ill-prepared concoctions still contain parts of the leaves and stem of the plant and this can cause severe liver damage and hepatotoxicity.

I've scoffed at Kava drinking before, but I had some last spring break as a part of a Hawaiian cultural experience. Despite its dirty brown yellow watery appearance and its strange numbing effect, it's not that bad. It's nothing that I would choose to drink, but I can see why many Polynesians drink it.

As for the effects of GGT, gamma-glutamyltransferase is a liver enzyme used like alkaline phosphatase (ALP) as a marker of liver damage. In conjunction with elevation in other liver enzymes like ALT and AST, an assessment of liver health is made.

I think it is irresponsible to imply that the elevated GGT levels signify something other than liver damage. If these enzymes that are normally in biliary liver cells are released into the blood stream in large amounts... to me, it means that they are dying off in larger amounts.

At least they end the article this way:

Even with the high GGT enzyme results of the UH study, the men said they aren't about to change their kava-drinking habits.

But Brown, the lead author of the study, said heavy kava drinkers might consider getting their liver functions tested.

"You want your liver profile to be normal," she said. "If something is causing that to be abnormal, then you should discuss it with your doctor and have your doctor run a liver profile. Then take your doctor's advice."

References:
Honolulu Advertiser, 9/22/07. "Hawaii kava study finds liver anomaly" http://the.honoluluadvertiser.com/article/2007/Sep/22/ln/hawaii709220345.html
Samoan Sensation. http://www.samoa.co.uk/drink.html
Wikipedia, “Kava.” 20067 http://en.wikipedia.org/wiki/Kava