Coffee
Consumption Reduces the Risk of Liver Cancer
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Coffee
Beans
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Over
the past 20 years, a body of data has accumulated that suggests
a clear benefit for liver
function and liver disease from drinking coffee. Several
studies have demonstrated that drinking coffee lowers gamma-glutamyltransferase
(GGT) activity, especially among heavy
alcohol drinkers. In a Japanese study of 2494 men, the
mean GGT was about 30% lower among those who drank 4 or more
cups of coffee daily compared to non drinkers.
Although GGT is a relevant indicator of the risk for cirrhosis,
serum alanine aminotransferase
(ALT) activity is a more specific marker of liver injury,
and a few population-based surveys from Italy and Japan have
found a similar inverse relation between coffee drinking and
ALT levels.
Results of a study by Gelatti et al published in the current
issue of the Journal of Hepatology (April 2005) provide
more evidence of an inverse relation between drinking coffee
and hepatocellular
carcinoma (HCC) [liver cancer].
The aim of this study was to investigate the role of coffee
in HCC, taking the main risk factors into account. Researchers
conducted the study in northern Italy, where they enrolled
250 hepatocellular (HCC) patients and 500 controls who had
been hospitalized for any reason other than neoplasms and
liver and alcohol-related diseases.
A standardized questionnaire provided information to the investigators
concerning the patients' lifetime history of coffee.
Results
Coffee consumption by the study group in the decade prior
to the questionnaire/interview was associated with a decreasing
risk of HCC with a clear dose-effect relation.
With respect to non coffee drinking participants, the odds
ratios (ORs) were: 0.8, for 1-2 cups/day, 0.4 for 3-4 cups/day
and 0.3 for 5 or more cups/day.
The ORs for HCC decreased for drinking >2, compared to
0-2 cups/day of coffee, for an alcohol intake >80g/day,
for presence of hepatitis B virus infection or hepatitis
C virus infection.
The
authors conclude, "Coffee drinking was inversely associated
with hepatocellular carcinoma regardless of its etiology."
Discussion
Compared with non coffee drinkers, the relative risks (RRs)
were 0.8 for drinkers of 1-2 cups per day, 0.4 for those of
3-4 cups, and 0.3 for drinkers of five or more cups per day.
The inverse relation between coffee and primary liver cancer
is stronger than in previous studies, indicating that the
relation is probably real, and not due to chance.
The combined, pooled RR from three published studies of coffee
and hepatocellular carcinoma for drinkers of three or more
cups of coffee per day as compared to non coffee drinkers
is approximately 0.6.
More important, the study by Gelatti et al. provides original
information on the independent effect of coffee from the major
recognized risk factors for primary liver cancer. The inverse
relation with coffee, in fact, was of similar magnitude in
subjects negative or positive for HBV or HCV serum markers,
as well as in non- or moderate drinkers and in heavy drinkers.
Coffee appears to have a real, but moderate effect in reducing
the risk of hepatocellular carcinoma. Various components of
coffee have been related to such a favorable effect, including
caffeine, coffee oils kahweol or cafestol, and antioxidant
substances from coffee beans, but no definite evidence is
available for any of these components.
Despite these uncertainties, HCC should be added to other
digestive tract cancers on which a favorable role of coffee
drinking has been suggested, including oral and pharyngeal,
oesophageal and colorectal cancers.
04/04/05
References
U Gelatti and others (for the Brescia HCC Study Group). Coffee
consumption reduces the risk of hepatocellular carcinoma independently
of its aetiology: a case-control study. Journal of Hepatology
42(4): 528-534. April 2005.
C La Vecchia. Coffee, liver enzymes, cirrhosis and liver cancer
(Editorial). Journal of Hepatology 42(4): 444-446.
April 2005.
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