A second study in the same journal suggests that
caffeinated coffee consumption is not tied to colorectal
cancer, although decaffeinated coffee may decrease the risk of
rectal cancer.
Dr. Manami Inoue and colleagues at the National Cancer
Center in Tokyo surveyed approximately 90,000 individuals in
1990 or between 1993 and 1994. The subjects were followed
through the end of 2001, during which time 334 were diagnosed
with liver cancer.
The risk of liver cancer among those who almost never drank
coffee was twice as high as for those who drank coffee on a
daily basis.
The investigators observed no association between green tea
intake and the risk of liver cancer, suggesting that
antioxidants unique to coffee may be responsible for its
protective effects.
In the second article, Dr. Karin B. Michels at Brigham and
Women's Hospital in Boston and colleagues analyzed data from
88,000 women in the Nurses' Health Study, which began in 1976,
and from 46,000 men in the Health Professionals' Follow-up
Study, which began in 1986. During followup through 1998, there
were 1433 cases of colorectal cancer.
Total coffee or tea consumption was not associated with the
development of colorectal cancer in either group.
However, among subjects who reported never drinking
decaffeinated coffee, the occurrence of rectal cancer was 58%
higher than among those who drank two or more cups per day.
While results were consistent for both cohorts, Dr.
Michels' group says the relationship of decaffeinated coffee to
a lower risk of rectal cancer should be looked at again in
additional studies.
SOURCE: Journal of the National Cancer Institute, February
16, 2005.
