CREDIT: WALLY MCNAMEE/CORBIS

There are about 18,000 people waiting for liver transplants in the United States, but only about 4500 new livers become available each year. A major source for livers are people who die on the road. But alcohol is a common player in accidents, so perhaps 30% of the livers that become available have fatty buildups, one of the early manifestations of heavy drinking. Alcohol causes fat formation by increasing production of triglycerides and blocking them from being passed out of the liver, says hepatologist Zhi Zhong of the University of North Carolina, Chapel Hill. Fatty livers put out more free radicals, which researchers believe may be responsible for primary graft failure, which occurs in about 10% of transplants.

But green tea extract might substantially enhance the fitness of transplanted livers, says Zhong. The researchers mimicked the bodily effects of a binge on mice by putting alcohol in their stomachs via a tube. They killed them 20 hours later, took out their livers--which already had started building up fat deposits--and infused them with a solution containing green tea extract, which is rich in free radical scavengers called polyphenols. The extract increased the survival of about 85 transplanted fatty livers from 13% to 75%, Zhong reported last month at the meeting of the American Physiological Society in New Orleans.

Previous rat studies by the group showed that consumption of green tea extract may stem liver damage from trauma or blood loss. Would drunks have more respectable livers if they also drank a lot of green tea? "I think so," says Zhong. Liver researcher Bin Gao of the National Institute on Alcohol Abuse and Alcoholism agrees that green tea appears to have a protective effect on the liver, but there are "so many components" in it that it's still not clear how it works.