Animal studies have suggested a protective association of coffee with liver cancer, so the research team led by Monami Inoue of the National Cancer Center in Tokyo analyzed a 10-year public health study to determine coffee use by people diagnosed with liver cancer and people who did not have cancer.
They found the likely occurrence of liver cancer in people who never or almost never drank coffee was 547.2 cases per 100,000 people over 10 years.
But for people who drank coffee daily the risk was 214.6 cases per 100,000, the researchers report in this week's issue of the Journal of the National Cancer Institute.
They found that the protective effect occurred in people who drank one to two cups of coffee a day and increased at three to four cups. They were unable to compare the effect of regular and decaffeinated coffee because decaf is rarely consumed in Japan.
''It's an excellent, interesting, and provocative study, and their conclusions seem justified," said Dr. R. Palmer Beasley of the University of Texas M.D. Anderson Cancer Center in Houston.
While the study found a statistically significant relationship between drinking coffee and having less liver cancer, the authors note that it needs to be repeated in other groups.
