(NaturalNews) A gut infection that is increasingly rare in wealthier countries actually reduces the risk of strokes and some cancers, according to a study conducted by researchers from New York University (NYU) and published in the journal Gut.
"The significance of this study is that this is a prospective cohort of participants representative of the U.S. population with a long follow-up," researcher Yu Chen said.
The bacterium in question, Helicobacter pylori (H. pylori), makes its home in the mucus lining of the stomach. The infection is very common in less wealthy countries, and more than half the world's population is estimated to carry the organism. Typically, it is transmitted between family members, and most people acquire it by the age of 10. Due to prevalent antibiotic use and modern sanitation practices, however, the bacterium is actually becoming quite rare in wealthier countries such as the United States.
Until recently, H. pylori was thought to be only a disease agent, as it has been implicated in numerous health afflictions including gastritis, peptic ulcers and stomach cancer. The varieties carrying a gene known as cagA are the most virulent, and have been considered among the greatest health concern.
Recently, however, NYU researchers discovered evidence that H. pylori infection may actually help protect children against asthma. The new study by the same researchers provides more evidence that our bodies' relationship with H. pylori is more complex than previously believed.
A protective infection?
The researchers examined health data - including H. pylori and cagA test results - on 7,384 people who had enrolled in the National Health and Nutrition Surveys (NHANES III) between 1988 and 1994. All participants were followed until 2000.
To their surprise, the researchers found that participants infected with H. pylori, including the cagA variety, had the same risk of death from all causes as participants who did not carry the bacteria. This was true even though H. pylori infected individuals had 40 times the risk of dying from gastric cancer as other participants. These data show, Chen said, that gastric cancer has now become uncommon in the United States.
"We studied both the overall H. pylori as well as cagA strain of H. pylori, which is more interactive with the human body," Chen said. "We found that H. pylori is not related to the risk of death from all causes, despite it being related to increased risk of death from gastric cancer."
Even more surprising, the researchers found that participants who were positive for the cagA strain of H. pylori - typically considered the most dangerous - actually had a 45 percent lower chance of dying from lung cancer and a 55 percent lower chance of dying from stroke than participants who tested negative.
"The most interesting finding was that there is a strong inverse association with stroke which could be protective," researcher Martin J. Blaser said. "There is some precedent for this and it is possible that the same cells (T reg cells) that H. pylori induces that protect against childhood asthma could be the protective agents."