Vegetarians less likely to develop cancer than meat eaters, says
study• Striking difference found in risk of disease in blood

http://www.guardian.co.uk/science/20...ncer-diet-risk
Karen McVeigh The Guardian

For years, they have boasted of the health benefits of their leafy
diets, but now vegetarians have the proof that has so far eluded them:
when it comes to cancer risks, they have the edge on carnivores.

Fresh evidence from the largest study to date to investigate dietary
habits and cancer has concluded that vegetarians are 45% less likely
to develop cancer of the blood than meat eaters and are 12% less
likely to develop cancer overall.

Scientists said that while links between stomach cancer and eating
meat had already been reported, they had uncovered a "striking
difference" in the risk of blood cancers including leukaemia, multiple
myeloma and non-Hodgkin lymphoma between the groups. The study looked
at vegetarians, fish eaters and people who ate meat.

Co-author Naomi Allen, from the Cancer Research UK epidemiology unit
at Oxford University, said: "Previous research has found that
processed meat may increase the risk of stomach cancer, so our
findings that vegetarians and fish eaters are at lower risk is
plausible. But we do not know why cancer of the blood is lower in
vegetarians."

She said the differences in cancer risks were independent of other
lifestyle factors including smoking, alcohol intake and obesity.

However, Allen urged caution over the interpretation of the findings.
"It is a significant difference, but we should be a bit cautious since
it is the first study showing that the risk of cancer of the blood is
lower in vegetarians. We need to know what aspect of a fish and
vegetarian diet is protecting against cancer. Is it the higher fibre
intake, higher intake of fruit and vegetables, is it just meat per
se?"

The study also reported that the total cancer incidence was
significantly lower among both the fish eaters and the vegetarians
compared with meat eaters.

The study, published in the British Journal of Cancer, is part of a
long-term international study, the European prospective investigation
into cancer and nutrition (Epic).

Today's findings were based on a study of 61,000 people who scientists
followed over 12 years. During this time, 3,350 participants were
diagnosed with cancer. Of those, 68% (2,204) were meat eaters, 24%
(800) were vegetarians and 9.5% (300) ate fish but no meat.

They found that 180 meat eaters developed blood cancers, while 49
vegetarians developed the diseases and 28 fish eaters. They found the
risk of being diagnosed with cancers of the stomach, bladder and blood
was significantly lower in vegetarians than in meat eaters but, in
contrast to earlier work, they found the rate of bowel cancer was
slightly higher among vegetarians than meat eaters.

A spokesman for BPEX, the British pig executive, questioned the
methodology of the study: "We are unable to take a view on this
because there is mixed evidence based on the compounding factors to do
with lifestyle that come into it."

Richard Lowe, the chief executive of Eblex, the English beef and lamb
executive, said: "We think that the link between diet and cancer is
complex and as scientists themselves say, more research is needed to
see how big a part diet plays."

The Oxford research is the latest in a series of reports to discourage
too much meat in the diet. Last year, Dr Rajendra Pachauri, chair of
the UN Intergovernmental Panel on Climate Change – which last year
earned a share of the Nobel peace prize – urged giving up meat at
least once a week as a way of combating global warming. The UN's Food
and Agriculture Organisation has estimated that meat production
accounts for nearly a fifth of global greenhouse gas emissions.

Two years ago, the World Cancer Research Fund found a link between red
and processed meat and bowel cancer and recommended that the average
amount of meat eaten should be no more than 300g a week. In Britain,
the current meat intake is about 970g a week for men and about 550g a
week for women.

In 2005, the Epic study, funded by the Medical Research Council,
Cancer Research UK and the International Agency for Research on
Cancer, concluded that eating just two portions of red meat a day –
the equivalent of a bacon sandwich and a fillet steak – increased the
risk of bowel cancer by 35%. It found that eating fibre, in the form
of vegetables, fruit and wholegrain cereals, lessened the risk of
cancer and that fish, eaten at least every other day, was also
protective.

Annette Pinner, chief executive of the Vegetarian Society, said: "It
is widely recognised that a third of cancers are directly related to
diet and what's interesting in this study is the findings on blood
cancers. We wouldn't claim vegetarianism is a panacea for cancer but
it is a step in the right direction."