Effects of Coffee Consumption against the Development of Liver Dysfunction: A 4-Year Follow-Up Study of Middle-Aged Japanese Male Office Workers

Abstract

The association of coffee consumption with the development of increased serum aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT) activities over 4 years was studied in 1221 liver dysfunction-free (serum AST and ALT ?39 IU/l and no medical care for or no past history of liver disease) Japanese male office workers aged 35 to 56 years. From the analysis using the Kaplan-Meier method, the estimated incidence of serum AST and/or ALT ?40 IU/l, ?50 IU/l, and ?60 IU/l decreased with an increase in coffee consumption. From the Cox proportional hazards model, coffee drinking was independently inversely associated with the development of serum AST and/or ALT ?40 IU/l (p=0.019 by test for tendency), ?50 IU/l (p=0.002), and ?60 IU/l (p=0.007), controlling for age, body mass index, alcohol intake, and cigarette smoking. These results suggest that coffee may be protectively against the liver dysfunction in middle-aged Japanese men.