What's the Link Between Coffee and Liver Disease?

Coffee and the liver

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For many years, I had cautioned my liver patients about consuming too much coffee under the assumption that it might aggravate hypertension and that the cream and sugar were unwanted extra calories. “Moderation in everything”, I preached.  Then several years ago, studies began to appear linking coffee consumption to improvements in liver disease. Specifically, it was demonstrated that coffee drinkers had lower ALT levels (ALT) and a lower rate of cirrhosis progression in hepatitis C cases and a lower risk of liver cancer.

  Similar findings are popping up for other liver disorders, including fatty liver disease. And the good news doesn’t stop with just liver diseases; coffee consumption may be beneficial for diabetes mellitus, Parkinson’s disease, heart disease and strokes (Medscape). Talk about reversing course!  What is it about coffee and how much needs to consumed to see the benefit?

Coffee and liver tests

It has been demonstrated repeatedly that coffee consumption is associated with lower levels of liver enzymes in the blood which are normally increased in liver injury (AST, ALT and GGTP).  One study from Italy demonstrated a 10% lower level of the liver enzyme ALT in those who drank 3 or more cups of coffee daily (Casiglia). This relationship has been confirmed in studies in the United States as well (NHANES).  GGTP is an enzyme that is associated with fatty liver and also with biliary obstruction. It is also associated with lack of response (or poor response) to interferon based therapy for HCV.

Coffee and liver disease

Several large studies have demonstrated that consumption of more than 3 cups of coffee daily was associated with improved outcomes in patients with alcoholic liver disease as well as nonalcoholic fatty liver disease. In patients with chronic hepatitis C, coffee ingestion has been associated with reduced scar formation and even with improved response to interferon therapy.

The same has not been demonstrated with hepatitis B, however. There is some evidence, though not as conclusive, that coffee consumption may also decrease the risk of liver cancer development in those with cirrhosis (Saab). This is an important observation that deserves even more attention.

Coffee or caffeine?

A study from Italy by Dr Modi in patients with chronic liver disease, it was shown that daily consumption of two or more cups of caffeinated coffee was associated with a reduced risk of liver scarring (Modi).  However, the same benefit was not achieved when the caffeine was from non-coffee sources. It seems from numerous studies, that the beneficial effect is only seen with filtered coffee (Medscape) and is not observed with espresso.  Tea, which also contains caffeine, has not been shown to have the same effect as filtered coffee. Coffee contains over 100 chemical and some may actually be harmful.  It is interesting that many of the harmful ones are removed by filtering.  Hence, the benefits of filtered coffee.

It is unclear whether there is any benefit to some of the newer coffee processes such as Nespresso or Keurig. These have not been specifically tested.

Bottom line

Although the exact mechanism for coffee’s beneficial effect is not known, the wealth of data demonstrating a beneficial effect on established chronic liver disease is impressive. Provided there are no medical or other health reasons not to drink coffee, it is likely that 3 or more cups of filtered, caffeinated coffee daily may improve liver tests, reduce the progression to cirrhosis and decrease the liver cancer risk.  You should note, however, that cream, sugar and other ingredients you add to your coffee may cause other obesity and liver-related issues.

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