Coffee Protects against Nonalcoholic Fatty Liver Disease

A daily dose of coffee (equivalent to six cups of espresso coffee for a 70-kg person) improved several key markers of nonalcoholic fatty liver disease (NAFLD) in mice that were fed a high-fat diet. [iStock/Heinz Trebuth]

Adding coffee to the diet of people with nonalcoholic fatty liver disease (NAFLD) could help reverse the condition, according to a new study conducted in mice and presented this week at The International Liver Congress in Barcelona, Spain.

The researchers found that a daily dose of coffee (equivalent to six cups of espresso coffee for a 70-kg person) improved several key markers of NAFLD in mice that were fed a high-fat diet. These mice also gained less weight than others fed the same diet without the dose of caffeine.

The scientists also showed how coffee protects against NAFLD by raising levels of a protein called zonulin-1 (ZO-1), which lessens the permeability of the gut. Experts believe that increased gut permeability contributes to liver injury and worsens NAFLD.  People suffering from NAFLD can develop scarring of the liver, also known as fibrosis, which can progress to a potentially life-threatening condition known as cirrhosis.

“Previous studies have confirmed how coffee can reverse the damage of NAFLD but this is the first to demonstrate that it can influence the permeability of the intestine,” said Vincenzo Lembo, Ph.D., at the University of Naples, Italy and study author. “The results also show that coffee can reverse NAFLD-related problems such as ballooning degeneration, a form of liver cell degeneration.”

Researchers analyzed three different groups of mice over a 12-week period. Group 1 received a standard diet, group 2 had a high-fat diet, and group 3 was given a high fat diet plus a decaffeinated coffee solution.

Coffee supplementation to a high-fat diet significantly reversed levels of cholesterol (p<0.001), alanine aminotransferase (levels of this enzyme increase in the blood when the liver is damaged) (p<0.05), amount of fat in the liver cells (steatosis) (p<0.001), and ballooning degeneration (p<0.05). The combination of coffee and a high-fat diet also reduced weight gain over time (p=0.028) in the mice. The study results suggest that coffee supplementation could cause variations in the intestinal tight junctions, which regulate the permeability of the intestine.

According to Professor Laurent Castera, secretary general of the European Association for the Study of the Liver (EASL), which sponsors the liver congress,  “Although not suggesting that we should consume greater levels of coffee, the study offers insights that can help future research into and understanding of the therapeutic role coffee can play in combating NAFLD.”