Food
and cancer
June 23, 2001
LONDON
(Reuters Health) - Almost one in three cancers could
be prevented through healthier eating, a major international
conference heard this week. Researchers making presentations
at the European Conference on Nutrition and Cancer in
Lyon, France, linked thousands of cases of cancer in
the western world to poor diet and a lack of exercise.
Conference attendees were also told of the preliminary
findings of one of the world's largest studies investigating
the relationship between the disease and what people
eat.
The
European Prospective Investigation into Cancer and Nutrition
(EPIC) - one of the biggest in terms of individual data
- has confirmed many previous studies showing that some
food can increase the risks of cancer while others can
have a protective effect on the human body. However,
it has also provided some new ideas and raised doubts
about previously long-held theories.
The
study, which is looking at the diets of more than 500,000
people from nine European countries, has confirmed once
again that eating fruit and vegetables can ward off
the disease, in particular colon and rectal cancer.
However, it casts doubts on the protective effects of
fruit and vegetables on other cancers. For instance,
the study found no evidence to suggest they can ward
off cancers of the stomach and lungs. "We do confirm
that the consumption of fruit and vegetables reduces
the risk of colorectal cancer and cancers of the mouth,
pharynx and oesophagus,'' Dr. Elio Riboli, one of the
organizers of the conference and one of those heading
up the study, told Reuters Health. "But we were
surprised not to find at this early stage a clear protection
for cancer of the stomach and lungs...for the time being
the protection for lung and stomach cancer is a little
weaker than we expected,'' he added.
The
preliminary results have also raised questions about
the long-held belief that eating red meat can increase
the risk of cancer. "For years there has been a
fear that red meat, particularly beef, lamb and pork,
could increase the risk of colorectal cancer,'' said
Riboli. "We have been looking very closely at this
issue and the results don't support that. We cannot
exclude a 10% to 15% increase for heavy consumption
of meat, but the risk is not as we may have thought
maybe 10 years ago.'' Riboli said the study would now
examine the effects of different meats. "This is
interesting because it is the first time a large study
has made a clear separation between processed and fresh
meat.
Previously,
we were only concerned with total meat consumption.''
He added, "We are now looking into the different
types of meat and why processed meat may be a greater
risk than fresh meat and to see what is in processed
meat that may increase the risks.''
The
study also highlights the long - established risks of
alcohol and tobacco. Its latest findings suggest that
smoking more than a pack of cigarettes each day can
increase the risk of cancer by eight times.
Similarly,
drinking a bottle of wine every day can boost the chances
of getting the disease by nine times. But the study
found that excessive smoking and drinking combined can
increase the risks by 50 times. Riboli acknowledged
that the findings could prove confusing for patients
who want to change their diet to protect against cancer.
"From the point of view of advice, one can only
have one diet and it is better that the diet is globally
healthy rather than aimed at just one particular cancer.
It has to take into account other diseases, such as
cardiovascular disease. It should not be focused on
just one particular cancer but on health generally,''
he said.
"We
continue to recommend that people have a diet which
has a little bit of everything but a lot fruit and vegetables
and not necessarily a vegetarian diet, that they eat
dairy products and remain physically active, don't smoke
and drink only in moderation,'' the researcher advised.
The study, which is ongoing, is not due to finish until
at least 2003. But the research team is planning to
publish a scientific paper examining the links between
cancer and food in 2002.