Tea and Coffee May Reduce Brain Tumor Risk According to EPIC Study
Daily intakes of more than
100 ml of tea or coffee may
significantly reduce the risk
of certain brain tumors,
according to new research
published in the American
Journal of Clinical Nutrition.
The study is based on data from over half a million people in
the European Prospective Investigation into Cancer and Nutrition
(EPIC) study, and finds that people consuming over 100 ml of
tea, coffee, or both, per day are at significantly lower risk of
glioblastoma tumours (glioma) than those consuming less than
100 ml per day.
"In this large cohort study, we observed an inverse association
between total coffee and tea consumption and risk of glioma,"
wrote the researchers from the Department of Epidemiology
and Public Health at Imperial College, London.
According to the American Brain Tumor Association, glioma's
are tumors that start in the supportive tissue brain. The exact
causes of gliomas are not known, however the prognosis for
people once diagnosed with the type of tumour is usually
very poor.
A recent US study found total coffee and tea consumption
was inversely associated with risk of glioma, whilst experimental
studies have shown caffeine can slow the invasive growth of
glioblastoma tumours.
However very few large scale epidemiologic studies have
measured the association between coffee, tea, or caffeinated
beverages and glioma risk. The authors noted that the results
of these studies "have been inconsistent".
"Given the limited evidence suggesting that coffee and tea
intake may reduce the risk of glioma, more studies are needed
to address this hypothesis," stated the researchers.
In the new study, the researchers examined the relation between
coffee and tea intake and risk of glioma and meningioma.
A significant inverse association was observed for glioma risk
when consuming more than 100 ml coffee and tea per day,
compared consuming less than 100 ml per day.
However, the researchers observed no association between
coffee, tea, or combined coffee and tea consumption and risk
of either type of brain tumor when looking at data based on
country-specific intakes.
No association was reported for meningioma risk with the
same intake values for coffee and tea intake combined,
or when a higher cutoff of 200 ml per day was used.
"Given that we did not observe an association between
coffee and tea consumption and meningioma risk, it is
possible that the effect of coffee, if causal, is acting late
in the process of carcinogenesis by preventing tumor growth,"
suggested the researchers.
Another potential mechanism that may be implicated in the
observed effects, involves the DNA repair protein MGMT.
Higher activation of MGMT is believed to have a protective
effect against development of several types of cancer,
including colon cancer and glioma.
Coffee compounds kahweol and cafestol have been reported
to increase MGMT activity in rats, whilst certain tea polyphenols
are known to reactivate genes in cancer cells - including MGMT.
"These findings, if further replicated in other studies, may
provide new avenues of research on gliomas," they added.
Source: American Journal of Clinical Nutrition Published online
"Coffee and tea intake and risk of brain tumors in the
European Prospective Investigation into Cancer and Nutrition
(EPIC) cohort study"
Editor's Note: This article is not intended to provide medical advice, diagnosis or treatment.