Coffee consumption and the risk of cancer: An overview
Research Center for Military Health, P.O. Box 906, Yaounde, Cameroon
Yaounde Military Hospital, P.O. Box 12794, Yaounde, Cameroon
a r t i c l e i n f o
Received 29 May 2008
Received in revised form 29 July 2008
Accepted 19 August 2008
a b s t r a c t
Habitual coffee drinking has been associated with a reduced risk of mortality and chronic
diseases, including cancer. The favourable influence of coffee is supported by several plau-
sible mechanisms due to the presence of a variety of biological compounds such as caffeine,
diterpenes, caffeic acid, polyphenols as well as volatile aroma and heterocyclic substances.
Current evidence suggests that coffee consumption is associated with a reduced risk of
liver, kidney, and to a lesser extent, premenopausal breast and colorectal cancers, while
it is unrelated to prostate, pancreas and ovary cancers. Coffee drinking may still help
reduce death due to liver cancer.
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Coffee is among the most widely consumed beverages
in the world and is top dietary antioxidant source in the
Nordic countries . Although some possible negative ef-
fects, such as spontaneous abortion and stillbirth have
been suggested during pregnancy , habitual coffee con-
sumption has been associated with a substantially lower
risk of mortality  as well as degenerative, progressive
and chronic diseases, including Alzheimer’s disease ,
Parkinson’s disease , type 2 diabetes , and coronary
heart disease .
The relationship between coffee and cancer holds great
interest, given a large array of compounds found in that
beverage that could potentially alter cancer risk through
several biological mechanisms. Coffee is the major source
of caffeine and some animal studies have reported caffeine
to both stimulate and suppress tumors, depending upon
the species and the phase of administration . Coffee con-
tains two specific diterpenes, cafestol and kahweal, which
produce biological effects compatible with anticarcino-
genic properties, including the induction of phase II en-
zymes involvedin carcinogen
specific inhibition of the activity of phase I enzyme respon-
sible for carcinogen activation and stimulation of intracel-
lular antioxidant defence mechanisms . Coffee is an
important source of polyphenols, such as lignan phytoes-
trogens and flavonoids  and polyphenols are found to
exhibit anticarcinogenic properties in several laboratory
and epidemiological studies [13,14].
Coffee is also a major source of the chlorogenic acid
that contributes to its antioxidant effect . Intake of
chlorogenic acid has been shown to reduce glucose con-
centrations in rats  and intake of quinides, degrada-
tion products of chlorogenic acid,
sensitivity . Chronic hyperinsulinemia and insulin
resistance are confirmed markers of high risk for some
cancer sites .
Hypermethylation of DNA is a common characteristic in
tumor cells and is a key epigenetic mechanism for silenc-
ing various genes, including those encoding the tumor
suppressor proteins, DNA repair enzymes, and receptors.
Gene-specific hypermethylation is known to be associated
with inactivation of various pathways involved in the
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Cancer Letters 277 (2009) 121–125
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