Eating processed meat promotes stomach cancer... err maybe

By Keren Sall

- Published: 18 August, 2006

The national press has made much of a new study which claims the more processed meat a person eats the more likely they are to develop stomach cancer.

But the sensationalist headlines and stories omit that the review, published in the Journal of the National Cancer Institute, appears to be confused. On the one hand ,

Susanna Larsson, who led the study at the Karolinska Institute's nutrition epidemiology divison, in Stockholm, Sweden, pointed out there is not enough evidence to say processed meat causes cancer and on the other she said it does. Confused?

The researchers claimed they reviewed 15 studies involving more than 4,700 people which were published from 1966 to 2006 on stomach cancer and processed meats, which included bacon, sausage, hotdogs, salami, ham, and smoked or cured meat.

NITRATES CONNECTION

Processed meats are often salted or smoked and have nitrates and nitrites added to them to extend shelf life, which, said the researchers, could be connected to the increased risk of stomach cancer. Nitrate and nitrites are an essential part of bacon manufacture, contributing to its characteristic flavour and colour.

Larsson said her research found that eating an additional 30g of processed meats a day was associated with a greater risk of stomach cancer. "Findings were most consistent for bacon consumption," she added.

However, such statements should be viewed with caution as researchers lumped studies from Europe, North America and South America all spanning a 20 year period, and with a total number of 4,700 people across 15 studies, the represenatitve groups were small. On top of this, the categories of processed meat consumption varied widely, ranging from less than 1g a day to more than 56g. It must also be pointed out that the studies did not all use the same standards, so Larsson's team bundled all the data together and did their own analysis.

Nitrates are used in cured meats to provide a buffer, which gradually releases nitrite and thus reduces the risk of botulism. Nitrites prevent the development of the naturally occuring spores of Clostridium Botulinum bacteria, and also inhibit the growth of other pathogens, such as salmonella and listeria. It seems Larsson and her team conveniently forgot to mention that 60% of nitrates in a daily diet come from vegetables, 15-25% from drinking water and only 2.5% from cured and processed meat. "If you are worried about nitrate levels then consumption of nitrates from processed and cured meat is not high on that list," said a spokesman for the MLC.

DBMC - REACTION

John Howard, from the Danish Bacon and Meat Council, agreed that the Swedish research was flawed. "Food surveillance studies in the UK and internationally have suggested that the amounts of nitrites consumed in cured meat are relatively insignificant compared with amounts produced by the body itself, and there is unlikely to be any risk of cancer from typical consumption levels of cured meats. In addition, the amount of nitrates consumed from other sources, e.g. water and vegetables, are larger than those consumed from bacon and other cured meats. The conclusion is that the benefits afforded by sensible use of nitrates and nitrites in cooked meats, in terms of food safety, far outweigh other minimal risks."

He added that the permitted levels of nitrate and nitrite incorporation in Danish bacon and ham are fixed by EU legislation.

VION - REACTION