Meat industry braces for report which could declare processed meats a cause of cancer

Britain's Independent newspaper wrote on Friday that the WHO "is expected to announce that the cancer threat from bacon and other processed meats is on a par with that of smoking". Photo / iStock

The New Zealand meat industry is trying to discredit reports that bacon and other processed meats are about to be declared a cause of cancer by a world research organisation.

The International Agency for Research on Cancer will at midnight (NZ time) issue a statement, following an evaluation, on whether it believes eating red meat and processed meats cause cancer.

The agency is part of the World Health Organisation (WHO).

Britain's Independent newspaper wrote on Friday that the WHO "is expected to announce that the cancer threat from bacon and other processed meats is on a par with that of smoking".

Tobacco smoking is listed by the International Agency for Research on Cancer (IARC) as "carcinogenic" -- a cause of cancer -- as are diesel engine exhaust, asbestos, sunlight and UV tanning machines.

Processed meats include sausages, bacon, ham and salami that have been preserved with methods such as curing, smoking, salting and the use of chemical preservatives.

Beef and Lamb New Zealand, which represents farmers and meat processors and retailers, says the forthcoming IARC announcement will be "a consensus statement based on existing research".

"There is no evidence to show any single food causes cancer," said the lobby group's spokeswoman Fiona Greig.

She said New Zealanders ate on average 22g of processed meat a day.

"The causes of cancer are many and complex with lifestyle factors playing a key role in reducing cancer risk including maintaining a [healthy] body weight, not smoking and avoiding high intakes of alcohol," she said.

"Processed meat contributes nutrients to the diets of Kiwis and eliminating it completely is unnecessary. It can be enjoyed in moderate portions with plenty of vegetables and as part of an active, healthy lifestyle."

Jim Mann, professor of human nutrition and medicine at Otago University, contributed to the World Cancer Research Fund's 2007 report on food, exercise and cancer, which found convincing evidence that eating red meat and processed meats increased the risk of bowel cancer.

Professor Mann says he does not know what IARC will say.

"I'm hoping there's new data that enables us to separate red and processed meats rather than lumping them together. It seems to me processed meat ? there's not a lot to recommend it, whereas moderate red meat consumption has got major nutritional benefits.

"What I've been told is that there's some new, potentially conflicting data. I'm surprised if they can make a definitive statement."

The Cancer Society's current advice states that red meats, including beef, lamb and pork, are "a valuable source of a number of different nutrients especially protein, iron, zinc and vitamin B12".

"It is recommended that people who eat red meat consume less than 500g a week, with very little, if any, processed meat. It is also recommended that care is taken when preparing and cooking red meat to avoid excessive fat intake and eating charred or burnt meat."

The World Cancer Research Fund says one possible reason for the strong evidence linking high red meat intake to bowel cancer is that "haem", the substance which gives the meat its colour, may damage the bowel lining.

"Studies also show that people who eat a lot of red meat tend to eat fewer plant-based foods, so they benefit less from their cancer-protective properties.

"When meat is preserved by smoking, curing or salting, or by the addition of preservatives, cancer-causing substances -- carcinogens -- may be formed. These substances can damage cells in the body, leading to the development of cancer."