High-fiber Diet Helps Prevent Colon Cancer
research counters studies that had questioned its
the latest evidence pointing to
the benefits of eating fiber, researchers on both
sides of the Atlantic report a high-fiber diet
sharply reduces the risk of colon cancer.
conclusion, in two studies in
a recent issue of The
reinforces earlier medical
advice recommending high-fiber diets. Other studies
in recent years have found high-fiber diets provided
no protection against colon cancer, calling into
question long-held beliefs.
MORE FIBER, LOWER CANCER
the European study, which the researchers called the
largest ever on the relationship between diet and
cancer, the scientists tracked
than a half million people in
10 countries for an average of 4.5 years.
averaged 35 grams of daily fiber intake had a 25
percent lower risk of colorectal cancer, primarily
colon cancer, compared with those who averaged 15
grams of fiber a day, the study found.
correlation proved strongest for colon cancer and
was not statistically relevant for rectal cancer,
the study says.
examination of more detailed dietary data
about 32,000 people in the
European study yielded even
promising results. It showed
that those who consumed 35 grams of fiber daily had
a 40 percent lower risk of cancer than those who ate
15 grams daily according to the study.
interesting thing is, it does actually confirm all
the other studies prior to the most recent ones,
which found no relationship between high-fiber diets
plant foods because then you're
whole-grain cereal, more fruits
study focused on 37,600 people, about 3,600 of whom
had non-malignant polyps- precursors of colon
cancer. Based on surveys, researchers divided the
people into five groups, according to their fiber
ate the most fiber, an average of 36.4 grams a day
had a 27 percent lower risk of the polyps than those
who ate the least fiber, averaging 12.6 grams a day,
the study found. To achieve those protective
effects, the latest research suggests, Americans
would have to consume much more fiber than they
currently do. The U.S. study says Americans average
about 16 grams of fiber a day.
The risk [of colon cancer] is
going down when the fiber is increasing; it's a very
strong trend. This is a positive finding because it
is consistent with health recommendations" for fiber
Both studies looked at fiber in
foods only, drawing no conclusions about the
potential protective value of fiber in dietary
It's "very strange" that some
earlier studies did not show the same protective
effects of fiber. Earlier research could have
mistakenly concluded fiber had no preventive effect
because of smaller amounts of fiber eaten and less
variety in the amounts and types.
principal investigator of the 2000 Polyp Prevention
Trial, says stands by its findings that a high-fiber
diet doesn't protect against colon cancer.
For 4 years, the Polyp Prevention
Trial followed almost 2,000 patients believed to be
at high risk for colon cancer because they had had
precancerous polyps removed.
them were told to follow a diet that included five
to eight servings of fruits and vegetables and at
least 18 grams of dietary fiber for every 1,000
calories a day, with no more than 20 percent of
their calories from fat. The other half of the study
participants got dietary counseling but did not
change their eating habits much.
The rate of recurrence of polyps
was the same for both groups in the "rigidly
It's not a major factor in
preventing colon cancer of fiber. We need to go on
to something that's more significant than fiber,
calling for more emphasis on screening for colon