
Life Extension Update Exclusive
A study that is the first of its kind to examine the relationship between coffee and tea consumption and chronic liver disease among Americans revealed that consuming the two or more cups of either beverage on a daily basis may be protective to high risk individuals. Chronic liver diseases include fibrosis, cirrhosis, and hepatitis, and can have a number of causes. The effect was seen in those at high risk of liver disease from being overweight, drinking heavily, being a diabetic, or having iron overload. The study was published online in Gastroenterology, the journal of the American Gastroenterological Association, and will appear in the December 2005 issue.
Constance E Ruhl, MD, PhD, of Social and Scientific Systems, Inc., in Silver Spring, Maryland and James E. Everhart, MD, MPH, of the National Institutes of Health in Bethesda analyzed data obtained from 9,849 data from the first National Health and Nutrition Examination Survey (NHANES I). Participants were asked about the number of cups of coffee and tea consumed daily in interviews conducted during 1971 to 1975, and were followed for an average of 19 years. A second analysis of 9,650 NHANES I Epidemiologic Follow-Up Study participants who were interviewed during 1982 to 1984 was also conducted.
During the follow-up period, 1.4 percent of the subjects developed chronic liver disease. Drs Ruhl and Everhart found that consuming more than two cups of coffee or tea per day was associated with less than half the risk of developing chronic liver disease than that experienced by those who drank less than one cup per day. When subjects who were at low risk and those who were at high risk of liver disease were analyzed separately, the protective benefit of drinking two or more cups of coffee and tea per day emerged only among those in the high risk group. Analysis of participants in the NHANES I Epidemiologic Follow-Up study revealed a similar association, however, the risk reduction was only statistically significant for coffee consumption.
Dr Ruhl stated, "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. In addition, we hope the findings will offer guidance to researchers who are studying liver disease progression."
"In the analysis, we determined that caffeine was partly responsible for the protective effect found,� Dr Ruhl added. �We believe that investigations into the mechanism of action of caffeine for protecting the liver and its clinical application are needed."