Processed meats - such as bacon, sausages and ham - do
cause cancer, according to the World Health Organization (WHO).
Its report said 50g of processed meat a day - less
than two slices of bacon - increased the chance of developing colorectal cancer
by 18%.
Meanwhile, it said red meats were "probably
carcinogenic" but there was limited evidence. The WHO did stress that meat also had health benefits.
Cancer Research UK said this was a reason to cut down
rather than give up red and processed meats.
And added that an occasional bacon sandwich would do
little harm.
What
is processed meat?
Processed meat has been modified to either extend its
shelf life or change the taste and the main methods are smoking, curing, or
adding salt or preservatives.
Simply putting beef through a mincer does not mean the
resulting mince is "processed" unless it is modified further.
Processed meat includes bacon, sausages, hot dogs,
salami, corned beef, beef jerky and ham as well as canned meat and meat-based
sauces.
It is the chemicals involved in the processing which
could be increasing the risk of cancer. High temperature cooking, such as on a
barbeque, can also create carcinogenic chemicals.
In the UK, around six out of every 100 people get
bowel cancer at some point in their lives.
If they were all had an extra 50g of bacon a day for
the rest of their lives then the risk would increase by 18% to around seven in
100 people getting bowel cancer.
"So that's one extra case of bowel cancer in all
those 100 lifetime bacon-eaters," argued Sir David Spiegelhalter, a risk
professor from the University of Cambridge.
How
bad?
The WHO has come to the conclusion on the advice of
its International Agency for Research on Cancer, which assesses the best
available scientific evidence.
It has now placed processed meat in the same category
as plutonium, but also alcohol as they definitely do cause cancer.
However, this does not mean they are equally
dangerous. A bacon sandwich is not as bad as smoking.
"For an individual, the risk of developing colorectal
(bowel) cancer because of their consumption of processed meat remains small,
but this risk increases with the amount of meat consumed," Dr Kurt Straif
from the WHO said.
Estimates suggest 34,000 deaths from cancer every year
could be down to diets high in processed meat.
That is in contrast to one million deaths from cancer
caused by smoking and 600,000 attributed to alcohol each year.
Red meat does have nutritional value too and is a
major source of iron, zinc and vitamin B12.
However, the WHO said there was limited evidence that
100g of red meat a day increased the risk of cancer by 17%.
The WHO said its findings were important for helping
countries give balanced dietary advice.
Prof Tim Key, from the Cancer Research UK and the
University of Oxford, said: "This decision doesn't mean you need to stop
eating any red and processed meat, but if you eat lots of it you may want to
think about cutting down.
"Eating a bacon bap every once in a while isn't
going to do much harm - having a healthy diet is all about moderation."
Dr. Teresa Norat, one of the advisors to the WHO
report and from Imperial College London, said there were many factors causing
bowel cancer.
She told BBC News website: "People should limit
consumption of red meat and avoid consuming processed meat, but they should
also have a diet rich in fibre, from fruit and vegetables and maintain an
adequate body weight throughout life and limit the consumption of alcohol and
be physically active."
The industry body the Meat Advisory Panel said
"avoiding red meat in the diet is not a protective strategy against
cancer" and said the focus should be alcohol, smoking and body weight.
Source: BBC.com