Drinking coffee may protect the liver especially for people who tend to drink alcohol also.
A long-term study of over one-hundred thousand people found coffee drinkers were less likely to be diagnosed with alcoholic cirrhosis, a condition where scar tissue forms on the liver as a result of too much alcohol.
Researchers found the more coffee a person drank the less likely they were to be diagnosed with that scarring. You'll find that study in the archives of Internal Medicine