Could Infections Harm Memory in Older Adults?
Early study found connection between exposure to microbes, poorer scores on mental-ability tests
"This time we looked at detailed cognitive [mental function] testing, both at the first time point and then also in a subgroup who we followed up with cognitive testing five years later," he added.
The researchers took into account and adjusted their results for important factors such as age, education, socioeconomics and high blood pressure.
"We are suggesting there is a link with vascular disease, that maybe there's a vascular link to worse cognition through this immune pathway. But the study doesn't explain why the infections are related to worsening cognitive function," said Wright, who added that it's too soon to suggest how it is that people who have been exposed to these common infections may be at risk for mental decline and stroke.
"We're not proving causation. There's no evidence yet that treating these infections will help," Wright said.
Dr. Larry Goldstein, director of the Duke Stroke Center in Durham, N.C., said, "This all fits together and makes some sense." He was not involved with the new study.
Goldstein said a variety of infections and inflammatory conditions have been associated with stroke and other vascular disease as well as mental impairment. "There's a big overlap between risk factors for vascular disease and stroke and Alzheimer's disease and cognitive issues," he said. "But right now people can't do a lot about it."
Study author Wright said in future research, one thing they could ask is who goes on to develop dementia or mental impairment. "But that's not what we did here," he said. "We just looked at crude associations with cognitive performance."
He also noted that the majority of the study participants were Hispanic, so more studies in other groups are warranted.
Because this study was presented at a medical meeting, the data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.