Connection between Processed Meats and Stomach Cancer

New research from Karolinska Institutet in Sweden has established that increased consumption of processed meat products such as bacon, sausages and smoked ham, increases the risk of developing stomach cancer. A survey of a large number of studies has shown that the risk of developing stomach cancer increases by between 15% and 38% when consumption of processed meat products increases by about a half-portion per day. Stomach cancer accounts for nearly 10% of total deaths from cancer.

The incidence of stomach cancer throughout the world has fallen during the last 50 years, but this form of cancer is still the fourth most common. Its mortality rate is so high that it is the second most common cause of cancer-related death. Approximately 700,000 deaths from this form of cancer occur every year throughout the world.

Processed meats are often salted or smoked, or nitrites may be added to them, in order to prolong their shelf-life. It may be the case that these treatments increase the risk of developing stomach cancer, but previous studies have given contradictory results.

"We decided to carry out a meta-analysis. This is an analysis in which we collated all research into processed meats and stomach cancer that we could find", explains Susanna Larsson, research student under the supervision of Alicja Wolk at The Institute of Environmental Medicine at Karolinska Institutet.

They found 15 studies, covering 4,704 subjects in the period 1966 2006, and the results are unequivocal: the risk of developing stomach cancer increases by between 15% and 38% when consumption of processed meat products increases by 30 grams (approximately a half-portion) per day.

"Nobody had carried out this type of analysis into processed meats and stomach cancer," says Susanna Larsson, "and our results from a mean value show very clearly that there is an association between increased consumption of processed meat products and stomach cancer. We hope that further studies will clarify the interaction between the consumption of processed meats and other factors, such as other dietary factors and the effects of different bacteria on the incidence of stomach cancer."