Coffee drinking has been suggested to protect against liver injury, but it is uncertain whether this is of clinical significance.
Dr Constance Ruhl and Dr James Everhart from Maryland examined the relationship of coffee and tea consumption with the incidence of hospitalization or death from chronic liver disease.
The research team assessed participants in the population-based, first National Health and Nutrition Examination Survey from 1971 to 1975.
The participants were asked about coffee and tea consumption, which was categorized as less than 1 cup, 1 to 2 cups, and more than 2 cups per day.
|The risk with more than 2 cups per day was less than half the rate than with 1 cup per day|
A second analysis included persons who, from 1982 to 1984, were asked more detailed questions on coffee and tea drinking.
The team reported that participants were followed through from 1992 to 1993 for a hospital or death certificate diagnosis of chronic liver disease or cirrhosis.
Hazard rate ratios for chronic liver disease according to coffee and tea intake were calculated using Cox proportional hazards analysis.
Among 9849 persons followed for a median of 19 years, the researchers found that the cumulative incidence of chronic liver disease was about 1%.
In multivariate analysis, those who drank more than 2 cups per day had less than half the rate of chronic liver disease as those who drank less than 1 cup per day.
The team noted that protection by coffee and tea was limited to persons at higher risk for liver diseases.
The higher risks for liver disease were from heavier alcohol intake, overweight, diabetes, or high iron saturation.
The team further assessed 9650 participants who provided detailed drink information in 1982 to 1984.
Among these participants, the team observed that intake of regular ground coffee and of caffeine was associated with lower incidence of chronic liver disease.”
Dr Ruhl and colleague concluded, “Coffee and tea drinking decreases the risk of clinically significant chronic liver disease.”