Heavy Drinking, Being Overweight, Diabetes

This protective effect was observed in people at higher risk for liver injury due to heavy drinking, being overweight, diabetes, or iron overload.

"While it is too soon to encourage patients to increase their coffee and tea intake, the findings of our study potentially offer people at high-risk for developing chronic liver disease a practical way to decrease that risk," researcher Dr. Constance E. Ruhl said in a prepared statement. "In addition, we hope the findings will offer guidance to researchers who are studying liver disease progression."

Caffeine Partly Responsible

The study was conducted by researchers from the US National Institute of Diabetes and Digestive and Kidney Diseases and from Social & Scientific Systems, Inc. They analyzed 19 years of data on nearly 10,000 people whose coffee and tea intake had been evaluated over time.

Reporting in the December issue of the journal Gastroenterology, the researchers found that people who drank more than two cups of coffee or tea a day developed chronic liver disease half as often as people who consumed less than a cup of tea or coffee a day.

"In the analysis, we determined that caffeine was partly responsible for the protective effect found. We believe that investigations into the mechanism of action of caffeine for protecting the liver and its clinical application are needed," Ruhl said.

More information: The American Liver Foundation has more about liver diseases.