“In both cohorts, we observed a suggestive positive association between seropositivity for T. gondii antibodies and glioma risk,” the researchers wrote. The glioma associations were stronger for the people who had higher levels of T. gondii antibodies.
Ť. gondii is a common parasite that most commonly infects people through contaminated food or water from raw or undercooked meat from infected animals. Twenty percent to 50% of the global population have been exposed to the parasite, according to the study.
Gliomas make up the majority — 80% — of malignant brain tumors. Glioblastomas are the most common subtype. Glioblastomas have five-year relative survival rates of only 5%.
“Our findings provide the first prospective evidence of an association between T. gondii infection and risk of glioma, results that should be confirmed in independent studies,” the researchers wrote.
“This does not mean that T. gondii definitely causes glioma in all situations. Some people with glioma have no T. gondii antibodies, and vice versa,” Hodge said in a statement.
“The findings do suggest that individuals with higher exposure to the T. gondii parasite are more likely to go on to develop glioma,” added Coghill. “然而, it should be noted that the absolute risk of being diagnosed with a glioma remains low, and these findings need to be replicated in a larger and more diverse group of individuals.”
If the findings of the study are replicated, “reducing exposure to this common food-borne pathogen would offer the first tangible opportunity for prevention of this highly aggressive brain tumor,” the researchers said.