Coffee consumption linked to reduced risk for liver cancer
People who regularly drink coffee may be half as likely to develop liver cancer as those who never or rarely consume coffee, according to a recent meta-analysis.
Researchers evaluated data from seven cohort and nine case-control studies assessing the effect of coffee consumption on the risk for liver cancer. The studies were collected via a search of Medline, Embase, ISI Web of Science and the Cochrane Library, and included research published in Asia (11 studies) and Europe (five studies) between 2000 and 2011.
Participants who reported high levels of coffee consumption were at 50% reduced risk for liver cancer compared with patients who never or almost never drank coffee, with a calculated summary OR of 0.50 (95% CI, 0.42-0.59), as well as an OR of 0.50 (95% CI, 0.40-0.63) across the case-control studies and an OR of 0.48 (95% CI, 0.38-0.62) among the cohort studies. Sensitivity analysis excluding one study with a mortality outcome did not alter the results (summary OR=0.49; 95% CI, 0.41-0.59), and no significant heterogeneity was observed.
The effect was determined to be more pronounced among men (OR=0.38; 95% CI, 0.25-0.56) than women (OR=0.60; 95% CI, 0.33-1.10) in a sub-analysis including four studies. The association also was observed when analysis was limited by study region (OR=0.45; 95% CI, 0.36-0.56 for Asian studies and OR=0.57; 95% CI, 0.44-0.75 for European studies). Adjustment for a history of liver disease reduced but did not eliminate this association (OR=0.39; 95% CI, 0.28-0.54 before adjustment and OR=0.54; 95% CI, 0.46-0.66 after).
The investigators said the study was limited by the inability to determine the impact of consuming different amounts of coffee, the possibility of misclassification bias, the geographical limitation to Asia and Europe and the possibility of publication bias.
“The results of this meta-analysis suggested that coffee consumption may be associated with a reduced risk of liver cancer,” the researchers wrote. “However, because of potential confounding, this finding should be treated with caution. Further, better-controlled studies are needed to confirm this finding.”