Drinking up to five cups of coffee a day may halve the risk of developing the most common form of primary liver cancer, researchers say.

The study, published in the journal BMJ Open, showed that the more coffee consumed, the greater was the protection against hepatocellular cancer (HCC) -- the second leading cause of cancer death globally.Drinking one cup more of caffeinated coffee a day was associated with a 20 percent reduction in the risk of developing HCC, two cups more with a 35 percent reduction."Coffee is widely believed to possess a range of health benefits, and these latest findings suggest it could have a significant effect on liver cancer risk," said lead author Oliver Kennedy from the University of Southampton.

"We're not suggesting that everyone should start drinking five cups of coffee a day though. There needs to be more investigation into the potential harms of high coffee-caffeine intake, and there is evidence it should be avoided in certain groups such as pregnant women," Kennedy added.In addition, decaffeinated coffee was also found to have a beneficial, though less marked, effect.The compound molecules found in coffee possess antioxidant, anti-inflammatory, anticarcinogenic and other beneficial properties which may lower the risk of chronic liver disease and liver cancer, the researchers explained.

"We have shown that coffee reduces cirrhosis and also liver cancer in a dose-dependent manner. Coffee has also been reported to reduce the risk of death from many other causes," commented Peter Hayes, Professor at the University of Edinburgh."Our research adds to the evidence that, in moderation, coffee can be a wonderful natural medicine," Hayes said.For the study, the team examined the data from 26 observational studies, involving more than 2.25 million participants, to calculate the relative risks of developing HCC for drinking between one and five cups of caffeinated coffee a day.