The research was conducted over 18 months on 1,100 liver clinic patients at Monash Medical Centre.
Dr Alex Hodge said the results showed coffee helps in fighting liver disease.
“We looked at patients with fatty liver, Hepatitis C and Hepatitis B, and we found that depending on sleep, and how much coffee you drink, there's a reduction in the amount of liver damage, or liver scarring,” he said.
In Hepatitis C patients, damage reduced by 13 per cent.
In fatty liver disease patients, which affects almost 40 per cent of Australians, damage was down 24 per cent.
He said the optimum amount of coffee for the two patient groups differed, with Hepatitis C patients deriving the most benefit from two cups of coffee a day, and fatty liver patients getting the best result with four cups.
But it is not known which blend is best, and what exactly it is in coffee that helps fight the illness.
“Caffeine is one of the constituents that’s been studied the most, and yes it does appear to have a benefit in people with liver disease based on cell culture work," he said. “But there’s a thousand other constituents in coffee and a lot of these probably have an effect.”
For those among the wider public who want to drink more than two to four coffees a day, there could be associated health benefits based on separate research from Harvard’s School of Public Health.
Thirty years of data was gathered from three ongoing studies of more than 200,000 participants.
It found that between three to five cups of coffee a day could extend life span, warding off premature death from cardiovascular and neurological disease, type-2 diabetes and lower the risk of suicide.
Lead report author and doctoral nutrition student Ming Ding said the benefits related to reduced inflammation.
"Bioactive compounds in coffee reduce insulin resistance and systemic inflammation," she said.
The research found both caffeinated and decaf coffee were effective.
