Coffee may reduce a person's risk of developing the most common type of liver cancer, hepatocellular carcinoma, by 40 percent, a new meta-analysis published in Clinical Gastroenterology and Hepatology found. The researchers also uncovered evidence that this number increases to 50 percent in the case that three cups are consumed every day.

The report looked at articles published between 1996 and 2012: In all, 16 studies and 3,153 cases were examined. According to the researchers, the study fills a significant research gap since the last meta-analysis on the subject was published in 2007. Since then, data on more than 900 cases of HCC has been published.

"Our research confirms past claims that coffee is good for your health, and particularly the liver," said Dr. Carlo La Vecchia, study author from the department of epidemiology, Istituto di Ricerche Farmacologiche 'Mario Negri,' and department of clinical sciences and community health, Università degli Studi di Milan, Italy. "The favorable effect of coffee on liver cancer might be mediated by coffee's proven prevention of diabetes, a known risk factor for the disease, or for its beneficial effects on cirrhosis and liver enzymes."

However, the researchers note, whether the relationship is causal or not is unclear. One possibility is that patients with liver and digestive diseases often reduce their coffee intake.

"It remains unclear whether coffee drinking has an additional role in liver cancer prevention," La Vecchia noted. "But, in any case, such a role would be limited as compared to what is achievable through the current measures."

Liver cancer is the sixth most common cancer in the world and the third most common cause of cancer death, the researchers note. Howevr, they estimate that as many as 90 percent of primary liver cancer worldwide could be avoided through hepatitis B vaccination, control of hepatitis C transmission and a reducing one's alcohol consumption.