Red meat excess a risk marker for cancer?

High consumption of red and processed meats - but not fat or cholesterol -could raise the risk of pancreatic cancer, claim researchers at the Cancer Research Center of Hawaii.

Tracking 190,000 consumers over seven years through a multiethnic cohort study, the scientists say participants in the highest quintile of processed meat intake had a 68 per cent increased risk of pancreatic cancer compared with those in the lowest quintile.

The yearly incidence rate of pancreatic cancer was 41.3 cases per 100,000 people in the highest quintile, compared with 20.2 cases per 100,000 in the lowest quintile, report the researchers in the October 5 issue​ of the Journal of the National Cancer Institute.​

Intakes of pork and red meat were both associated with 50 per cent increased risks of pancreatic cancer when comparing the highest and lowest quintiles.

But the authors found no associations between intakes of poultry, fish, dairy products, eggs, total fat, saturated fat, or cholesterol and pancreatic cancer risk.

They suggest that because fat is not likely to contribute to the mechanism underlying the findings for meat consumption, instead carcinogenic substances resulting from meat preparation techniques could be linked to the increase in pancreatic cancer risk.

In the US, nearly 32,000 Americans were diagnosed with pancreatic cancer last year - the five year survival rate is less than 5 per cent.

This latest study follows hot on the heels of a massive European funded research that concluded red and processed meat consumption increases the risk of colorectal cancer.

The European Prospective Investigation into Cancer and Nutrition (EPIC), that spanned ten countries and tracked nearly half a million consumers, concluded colorectal risk increases by 49 per cent per 100 grams of daily consumed red meat, to cover pork, beef, veal, and lamb.

Their findings prompted an immediate reaction from the meat industry that claimed the study fails to "prove cause and effect".

Defending its industry, the American Meat Institute Foundation accused the study of being epidemiological, "which means it does not prove cause"​.

The group vowed the study's relative risk of 1.71 should be viewed with 'sceptism', and quotes the epidemiologist Ernst Wynder who, in the American Journal of Epidemiology​ in 1986, said relative risks under 3.0 are suspect.

"We should not rush to judgment about a causative implication when in fact the word 'association' ought to be used,"​ said Wynder.