Diet May Cut Cancer Risk
Eating a meat-free, vegetarian
diet may reduce the risk of colorectal cancer, new research suggests.
After following more than 10,000
people for 17 years, investigators found that vegetarians were
15 percent less likely to develop colorectal cancer than meat-eaters.
This study adds to the "increasing
scientific evidence" that a diet rich in fruit, vegetables and
fiber and low in meat--especially red and processed meat--can
prevent colorectal cancer, study author Dr. Miguel Sanjoaquin
of the University of Oxford, UK, stated.
However, Sanjoaquin cautioned that
only a small number of study participants -95--developed colorectal
cancer, making it impossible to determine if fewer vegetarians
developed cancer simply due to chance.
However, Sanjoaquin noted that
a previous study featuring more cases of colorectal cancer confirmed
these findings, and he added that it makes sense that eating vegetarian
could cut cancer risk. The fat in red meat increases the excretion
of substances called bile acids, he explained, which in turn produce
other substances that encourage tumor growth.
Furthermore, meat contains natural
compounds and substances formed during processing and high-temperature
cooking that can disrupt the normal balance of cell growth in
the colon, potentially triggering the cancer, Sanjoaquin noted.
Alternatively, substances in fruits
and vegetables-- staples of the vegetarian diet--"may inhibit
these adverse effects," he added.
During the current study, Sanjoaquin
and his colleagues asked 10,998 adults about their eating habits
and other health parameters, then noted who developed colorectal
People were classified as non-vegetarians
if they ate meat or fish. Vegetarians included vegans, who avoid
all dairy and meat products.
Along with a decreased risk of
cancer from eating vegetarian, the investigators found that frequent
fruit eaters - consuming more than 5 servings of fruit per week--were
over 40 percent less likely to develop colorectal cancer.
Smoking, drinking alcohol and eating
more than 15 slices of white bread per week appeared to increase
the risk of colorectal cancer, according to the British Journal
of Cancer report.
Sanjoaquin said the fact that white
bread appeared to reduce cancer risk was "unexpected," and suggested
that people who ate large amounts of white bread might have simply
had a less healthy diet overall.
Alternatively, he added researchers
have noted that eating large quantities of refined carbohydrates,
such as those found in white bread, may raise colorectal cancer
risk, suggesting that white bread itself may also play a role.
"More research will be needed to
clarify this," Sanjoaquin said.
SOURCE: British Journal of Cancer,
January 12, 2004.
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