Researchers asked nearly 19,000 Finnish men and women between ages 25 and 74 about their coffee and alcohol consumption.
"Our findings suggest a possible protective effect for coffee intake in alcohol consumers," said study researcher Dr Onni Niemela, of Seinajoki Central Hospital and the University of Tampere in Finland.
Researchers measured participants' blood levels of the liver enzyme gamma-glutamyl transferase (GGT), MyHealthNewsDaily reported.
Drinking alcohol raises levels of GGT in the blood. Over time, drinking can also lead to alcoholic liver disease. People with liver disease show higher levels of GGT in their blood.
More From This Section
But among the men who were heavy drinkers, those who also consumed five or more cups of coffee daily showed a 50 per cent reduction in GGT compared with men who drank no coffee.
The researchers found no significant association between coffee consumption and GGT levels in female drinkers.
In addition to drinking alcohol, smoking, older age and being overweight can also raise GGT levels.
The researchers found that the way that coffee was prepared - whether it was filtered, boiled or served as espresso, for example - did not seem to make a difference in the findings.
Previous studies have suggested that drinking coffee may decrease GGT levels, and that caffeine may play a role in this.
It remains unclear whether elevated levels of the liver enzyme correlate with symptoms of liver disease.