2009-09-13 06:48:15
Eating lots of red meat is linked with DNA damage which raises the risk of
bowel cancer, researchers suggest.
Scientists at the MRC Dunn Human Nutrition Unit and the Open University
compared red meat and vegetarian diets.
Their study, published in Cancer Research, found the red meat diet was
associated with a higher level of DNA damage.
Previous work suggests regular meat eaters are significantly more likely to
develop bowel cancer.
Almost 17,000 people die from the disease each year.
Clues
Last year the Dunn team published a study suggesting the chance of developing
the disease was a third higher for people who regularly ate more than two
portions per day of cooked red meat compared with those who ate less than one
portion per week.
These combined discoveries ... may give us some clues about developing a
screening test for very early changes related to the disease
Professor David Shuker, Open University
In the latest study the same Dunn team examined cells from the lining of the
colon taken from healthy volunteers eating different diets.
They found higher levels of DNA damage in the cells taken from people eating
red meat.
Work by the Open University team suggests the reason could be the presence of
substances called N-nitrosocompounds, which form in the large bowel after
eating red meat.
Their work suggests that these compounds combine with DNA, and alter it so that
it is more likely to undergo harmful changes or mutations that increase the
likelihood of cancer
Professor David Shuker, head of the Open University team, said: "These combined
discoveries have allowed us to link red meat consumption to an increased risk
of bowel cancer and may give us some clues about developing a screening test
for very early changes related to the disease."
'Moderation is key'
Professor Colin Blakemore, chief executive of the Medical Research Council,
which funded the research, said: "Large bowel cancer is the second most common
cancer in western countries and nearly one million cases occur each year
worldwide.
"This latest study, together with the compelling epidemiological evidence
published last year, is an important step towards understanding, and
potentially preventing this common disease."
A spokesman for the charity Beating Bowel Cancer said: "The fact is a third of
all cancers are linked to what we eat and we must not underestimate the
importance of a well-balanced diet in the prevention of bowel cancer.
"This study certainly seems to add further weight to previous evidence about
the possible link between bowel cancer and a high consumption of red meat.
"As with all dietary advice, moderation is key as we already know that a diet
high in fat and red meat yet low in fibre, fruit and vegetables can increase
the risk of developing this disease - currently the second biggest cause of
cancer death in the UK."
Professor Annie Anderson, expert advisor to Bowel Cancer UK, said: "The new
data not only provides further evidence of risk but also flags the importance
of what we eat with our meat - for example, there is further risk with low
fibre intakes.
"Current data on eating trends suggests we are eating more fast foods, which we
know are high in calories and fat and implicated as a cause of obesity and
diabetes, but such cuisine may also be the very type of meals (high in meat -
and meat products - and low in vegetables) that also contributes to bowel
cancer risk."
But a spokesman for the Meat and Livestock Commission said: "The results of
this very small-scale study merely suggest a mechanism by which red and
processed meat might possibly increase an individual's risk of developing
colorectal cancer.
"The authors themselves acknowledge that larger-scale, prospective studies are
needed to identify how important and robust this suggested mechanism could be."