High-Salt Diet and Stomach Bug Increase Risk of Cancer
Researchers from Vanderbilt University found that a diet high in salt combined with infection with Helicobacter pylori significantly increases one’s risk of gastric (stomach) cancer. Although many epidemiologic studies have shown that a high salt diet is associated with an increased risk of gastric cancer, Timothy L. Cover and colleagues report recently in the journal Infection and Immunity that in the presence of H. pylori bacteria that produces the oncoprotein known as CagA, a salty diet increases the risk further.
H. pylori is a type of bacteria that inhabits the human stomach in 50% of the population. Although this microorganism is associated with the development of stomach ulcers and gastric cancer, most people who harbor the bacteria do not have symptoms.
The study involved Mongolian gerbils, which were infected with H. pylori and divided into two groups. One group received a regular diet while the other fed on a high salt diet. In the end, all gerbils that fed on a high salt diet developed stomach cancer while only half of those which fed on a regular diet developed the disease.
The investigators also report that there was significant gastric inflammation in H. pylori-infected gerbils on a high salt diet compared to those on a regular diet, a factor that is common in many types of cancer. They also found that transcription of various inflammatory cytokines, such as interleukin 1-beta, were elevated in gerbils feeding on a high salt diet compared to the other group, which may contribute to the increased inflammation and increased gastric risk related to a high salt diet.
The authors also note that only gerbils which were infected with cagA+ H. pylori on a high salt diet developed cancer, while those that were infected with a mutant H. pylori that did not produce CagA did not develop the disease.
American Society for Microbiology. High-salt diet and ulcer bug combine to increase risk of cancer. ScienceDaily.