A new study suggests that herpes simplex, the virus that causes cold sores, may also have a negative impact on long-term cognition and memory.
The new study also revealed that other viral and bacterial infections may also increase the risk for developing cognitive issues.
Researchers aimed to investigate whether a connection between infection and memory exists and found that those individuals who were exposed to higher levels of infection for an extended amount of time experienced more problems related to memory than those who had lower levels of infection.
The theory exists on the idea that inflammation caused by infection has a negative impact on cognitive function.
"The idea is that these pathogens - both virus and bacteria - they might affect blood vessel walls, leading to vessel inflammation within the brain, which is associated with vascular dementia," the study's lead author Dr. Mira Katan from the Northern Manhattan Study at Columbia University Medical Center in New York and member of the American Academy of Neurology told FoxNews.com. "That's one possible connection."
"The other idea is that these pathogens are directly neurotoxic, meaning they might enter the brain and affect brain tissue and neurons directly," she explained.
In the new study, researchers evaluated antibody blood levels in 1,625 people who live in Manhattan with the average age of 69 and tested for three different low-grade viruses: oral herpes simplex type 1, genital type 2 and cytomegalovirus as well as chlamydia pneumoniae.
Study participants were monitored for about eight years on average and during that time, researchers conducted memory and thinking skill testing annually.
The results showed that the subjects with higher levels of infection had a 25 percent increased risk for developing memory-related issues than the others who had lower levels of the infection.
"We found actually that a mathematical combination of all these pathogens is associated with cognition problems," Katan said.
"It's not just one pathogen, but the cumulative burden of all these infections. So it's bad if you have one infection, but it's worse if you have several infections. This effect of several infections was associated with cognitive impairment."
But even with these findings, the results failed to show that infection continued to decrease cognitive function over time.
Katan said that more research needs to be done in regard to a possible link between infection and cognitive function so that early intervention via vaccination is encouraged in the future.
(SOURCE)