New research has linked exposure to common infections to poor brain function and memory, even without contracting the illness.

According to a press release from the American Heart Association, the study shows that various infections caused worse cognitive performance, abstract thinking, planning, reasoning as well as slower memory and mental processing.

"We were very interested in what were the risk factors for cognitive performance and decline," study lead researcher Clinton Wright, scientific director of the Evelyn F. McKnight Brain Institute at the University of Miami, said in the release.

For the study, the researchers took blood samples from 588 people participating in the Northern Manhattan Study and who took brain tests. About half the participants took another brain test five years later, but the study was not able to explain the link between worse cognitive function and exposure to common infections.

"It could be caused by an immune system response to the infections or the infection itself could result in clinical damage that we're not aware of," Wright said.

What's more is the study found common infections also lead to a higher stroke risk, as well as an increase in atherosclerosis and inflammation.

"Children who'd had a stroke were most likely to have had a recent infection compared to controls [children without stroke]," Dr. Heather Fullerton, an author involved in another study, told HealthDay News. "There was a particularly strong association for an infection in the week before a stroke, almost a sevenfold increase in the risk of stroke."

She said there is not nearly enough evidence to suggest there is a serious risk for any child, but noted the link was there.

"Clearly, infections are very common and stroke is very rare in children. What's going on is that infections are acting as a trigger for stroke in children who are likely predisposed to stroke," she said.

Wright said further research still needs to be conducted, because he said there is not yet any evidence that suggests these negative effects can be reversed.

"There is no evidence yet that treating these infections is beneficial," Wright said in the release. "It would be great if treatment prevented these bad outcomes, but we're very far away from having that type of evidence."