Increased caffeine consumption is associated with reduced hepatic fibrosis

Although coffee consumption has been associated with reduced frequency of liver disease, it is unclear whether the effect is from coffee or caffeine and whether there is an effect on hepatic fibrosis specifically. This study was undertaken to use a food-frequency instrument for dietary caffeine consumption to evaluate the relationship between caffeine intake and liver fibrosis. Patients undergoing liver biopsy completed a detailed caffeine questionnaire on three occasions over a 6-month period. Caffeine intake was compared between patients with mild and advanced liver fibrosis (bridging fibrosis/cirrhosis). Logistic regression was used to evaluate the association between caffeine consumption and hepatic fibrosis. One hundred seventy-seven patients (99 male, 104 white, 121 with chronic hepatitis C virus [HCV] infection) undergoing liver biopsy completed the caffeine questionnaire on up to three occasions. Results from repeated questionnaires were consistent. Daily caffeine consumption above the 75^th percentile for the cohort (308 mg = approximately 2.25 cups of coffee equivalents) was associated with reduced liver fibrosis (odds ratio [OR], 0.33; 95% confidence interval [CI], 0.14-0.80; P = 0.015) and the protective association persisted after controlling for age, sex, race, liver disease, body mass index, and alcohol intake in all patients (OR, 0.25; 95% CI, 0.09-0.67; P = 0.006), as well as the subset with HCV infection (OR, 0.19; 95% CI, 0.05-0.66; P = 0.009). Despite amodest trend, consumption of caffeine from sources other than coffee or of decaffeinated coffee was not associated with reduced liver fibrosis. A reliable tool for measurement of caffeine consumption demonstrated that caffeine consumption, particularly from regular coffee, above a threshold of approximately 2 coffee-cup equivalents per day, was associated with less severe hepatic fibrosis.