The effects of regular daily coffee consumption on liver enzymes were
studied in a large number of subjects from the general population. In
coffee drinkers, liver enzymes (gamma-glutamyl transferase, alanine-am
ino transferase, and alkaline phosphatase) and serum bilirubin were lo
wer than in non-coffee-drinking subjects or in those consuming less th
an 3 cups daily. The hypothesis proposed is that liver enzymes are a t
arget for caffeine contained in coffee.