Coffee and tea lovers may have a slightly reduced risk of
developing kidney cancer, research hints.
The findings, based on an analysis of 13 previous studies,
suggest that coffee and tea may be protective against kidney
cancer, while milk, soda and juice seem to have no effect one way
or the other.
Across the studies, people who drank three or more cups of
coffee a day were 16 per cent less likely to develop kidney cancer
than those who averaged less than a cup per day. And those who
sipped just one cup of tea each day had a 15 per cent lower risk of
the disease than non-drinkers.
The findings appear in the International Journal of Cancer.
While the study cannot show that coffee or tea directly lower
kidney cancer risk, there are reasons why the beverages could be
beneficial, according to the researchers, led by Dr Jung Eun Lee of
Harvard Medical School in Boston.
For example, they explain, coffee and tea may increase the
body's sensitivity to the blood-sugar-regulating hormone insulin,
and researchers suspect that insulin levels over time may affect
kidney cancer risk.
Coffee and tea also contain antioxidant compounds that may help
protect cells in the kidney from cancer-promoting damage, the
researchers point out.
For their study, the investigators combined the results of 13
long-term studies that included a total of 530,469 women and
244,483 men. Each study collected information on participants'
diets at the outset and then followed them for seven to 20
years.
Coffee and tea consumption were linked to a lower risk of kidney
cancer even when the researchers accounted for a number of factors
known to affect people's risk of the disease – such as obesity,
smoking and high blood pressure.
"Our results suggest that coffee and tea consumption may be
associated with a modestly lower risk of (kidney) cancer, whereas
intakes of milk, juice and soda were not associated with risk,"
Lee's team writes.
They say more studies are needed to understand why coffee and
tea might be protective against the disease.
(Agencies via China Daily December 26, 2007)
