There is increasing body of evidence that coffee has beneficial effects on liver disease. This is very good news considering that liver disease kills about two million people in the world every year. One million dies from the cirrhosis of the liver and its complications and one million dies yearly from viral hepatitis and hepatocellular carcinoma. Exactly which of more than 1000 active ingredients in coffee are responsible for the positive effects on liver disease is still under debate, but the research points towards antioxidants.
Some studies show that the diterphenes in coffee were responsible for the activation of UGT enzymes involved in the liver detoxification. Kahweol and cafestol enhance the production of chemoprotective enzymes glucuronosyl transferase and glutathione transferase. The antioxidants polyphenols, especially CGA, explain some of metabolic benefits of coffee, showing powerful anti-oxidant activity in studies.
A comprehensive 2019 literature review came up with the conclusion that drinking coffee potentially reduces the risk of liver cancer. A 2017 meta-analysis concluded that drinking coffee seems to reduce the risk of liver cancer, cirrhosis and nonalcoholic fatty liver disease. A 2014 study suggested coffee consumption might lower the mortality risk from non-viral hepatitis-related cirrhosis, reducing the risk by 66%. As early as 1985 in the Tromsø Heart Study scientists noted that coffee consumption decreased levels of aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT), alanine aminotransferase (ALT), and alkaline phosphatase (ALP). Since then, numerous studies confirmed the link between the consumption of three or more cups of coffee daily and the levels of liver enzymes.
In a 2015 a large study confirmed that the coffee consumption reduces mortality from chronic liver disease. Just one cup of coffee daily decreased the risk of death from chronic liver disease by 15 percent. Four cups a day lowered that risk by 71 percent. A number of studies also confirmed reduced frequency of fibrosis among coffee drinkers and a Norwegian study confirmed “an inverse association between coffee consumption and liver cirrhosis.“ Interestingly, the hepatic fibrosis seems to be affected by coffee and not any other caffeinated beverages.