Coffee consumption may help lower the risk of developing diabetes, cardiovascular disease, non-alcoholic fatty liver disease, cirrhosis, and liver cancer. Qian Xiao and colleagues, National Cancer Institute, Bethesda, Maryland, USA, used data from the U.S. National Health and Nutrition Examination Survey (NHANES, 1999-2010) to show that higher coffee consumption, regardless of caffeine content, is linked to lower levels of abnormal liver enzymes.

In 27,793 participants, 20 years of age or older, who provided coffee intake in a 24-hour period, the team measured blood levels of several markers of liver function, including aminotransferase (ALT), aminotransferase (AST), alkaline phosphatase (ALP), and γ-glutamyl transaminase (GGT) to determine liver health. Participants who reported drinking three or more cups of coffee per day had lower levels of ALT, AST, ALP, and GGT compared to those not consuming any coffee. Participants drinking only decaffeinated coffee also showed low levels of these liver enzymes.

The researchers conclude that ingredients in coffee, other than caffeine, may promote liver health. Further studies are needed to identify these components.

• Inverse associations of total and decaffeinated coffee with liver enzyme levels in NHANES 1999-2010,
  Qian Xiao, Rashmi Sinha, Barry I. Graubard, Neal D. Freedman,
  Hepatology 2014.
  DOI: 10.1002/hep.27367