NZ researchers find even moderate red meat eaters are at risk of bowel cancer

Kiwi researchers have found even people who eat a moderate amount of red meat are still at much higher risk of getting bowel cancer.

Auckland University scientists looked thousands of cases of people who developed the disease and found some alarming facts about their diets, in the new study Diet and colorectal cancer in UK Biobank: a prospective study, published in the International Journal of Epidemiology.

New Zealand has one of the highest bowel cancer rates in the world, and eating red meat has long been known to increase our risk.

But what's surprised researchers at Auckland University is just how little can be dangerous. 

"Think less beer and bacon, more bran and brown bread," says Dr Kathryn Bradbury, a senior research fellow in the School of Population Health at the University of Auckland.

"No matter where you start, if you reduce it down, you're probably going to be reducing your risk of bowel cancer."

The New Zealand health recommendation is to eat no more than 500 grams of red meat a week. But this study finds those who consumed that amount still had a higher bowel cancer risk than those who ate less.   

The research found people eating about 76 grams of red and processed meat per day - barely a mouthful above the recommended upper limit of 71g daily average - had a 20 percent higher chance of developing bowel cancer than those who only ate about 21g per day.

The risk rose 19 percent with every 25g of processed meat (roughly equivalent to a rasher of bacon or slice of ham) people ate per day, and 18 percent with every 50g of red meat consumed (a thick slice of roast beef or the edible bit of a lamb chop).

It also found each bottle of beer or small glass of wine raised bowel cancer risk by eight percent.

No link was found between bowel cancer risk and fish, poultry, cheese, fruit, vegetables, tea and coffee.

Beef + Lamb NZ said the association between red meat and cancer is not new, but "overall dietary and exercise patterns are more important than individual foods or the components that make up those foods" when it comes to risk.

"Red meat is an important source of essential nutrients required for growth, brain development and general wellbeing and the amount consumed should meet dietary goals as well as nutrient requirements, particularly in infants, toddlers and women of child-bearing age who are at risk of iron and zinc deficiency."

Dr Bradbury says unprocessed red meat can be healthy for iron levels and perhaps even for other diseases, so doesn't recommend cutting meat out completely, just reducing consumption.

But she says there's "substantial evidence" linking processed meat to bowel cancer.

"The risk for processed meat is about twice as strong as it is for red meat," she says.

So perhaps leave the likes of bacon and salami out of your diet.