Severe food poisoning caused by salmonella increases risk of colon cancer

17 January 2018• PRESSRELEASE

Persons who contract severe food poisoning caused by a specific salmonella bacterium have up to three times more chances of suffering from colon cancer. This is the result of a recent study of the Leiden University Medical Center (LUMC), the National Institute for Public Health and the Environment (RIVM), the Antoni van Leeuwenhoek Hospital, and the VU university medical center in Amsterdam.

Their findings were published recently in the academic journal PLOS ONE. “Just for comparison: eating red meat increases the risk of getting colon cancer by 1.2 times” according to Sjaak Neefjes, Professor of Chemical Immunology at the LUMC. The infection is caused by Salmonella enteritidis, a bacterium occurring in chicken products and raw eggs. “If you heat your food thoroughly, you will be fine.” 

A nation-wide study

Since some time, Prof. Neefjes has tackled the question whether salmonella bacteria increase the risk of cancer. He has shown before how salmonella turns healthy cells into cancer cells and has repeated this in laboratory animals. He saw how these animals caught colon cancer after a severe infection with salmonella. This was the reason for him to start a new, nation-wide study.

This study included examining the data of approximately 160,000 patients suffering from colon cancer, circa 30,000 of whom had earlier been the victim of food poisoning caused by salmonella infections. “These patients are severely ill because of such an infection, they visit their GP or medical specialist and are diagnosed with ‘salmonella’. The RIVM keeps track of how many Dutch people are infected by this bacterium,” Prof. Neefjes explains. With the help of Statistics Netherlands, these data have been linked to the database of the Dutch Cancer Register which keeps track of how often different types of cancer occur in the Netherlands.

Earlier studies

It turns out that a diagnosed infection with Salmonella enteritidis increases the chances of somebody getting colon cancer up to three times. “This is an important finding with many consequences, but it should be used carefully. For it is still possible that another cause exists for this link, even if we haven’t found it,” according to Prof. Neefjes. That is why he and his colleagues will carry out a similar kind of study abroad so as to confirm the Dutch findings. The outcome of this study will be of importance for the National Health Council, the advisory body that establishes who qualifies for screening for colon cancer.

The publication is to be read on the website of PLOS ONE.

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