Do You Get Sick a Lot? It May Increase Your Risk of Dementia
Michelle Milliken
Past research has found that common viruses are linked with the development of dementia, and that olfactory inflammation stemming from viruses may also hasten the onset of Alzheimer's. A new study provides more evidence of the virus-dementia link.
Research recently published in the journal Brain, Behavior and Immunity, and conducted in partnership with the National Institutes of Occupational Safety and Health, examined the impacts of inflammation caused by viruses like the cold and flu on the brains of aging mice. They found that repeated, intermittent experiences with this type of inflammation was linked with impaired cognition and disrupted communication between neurons.
Dr. Elizabeth Engler-Chiurazzi, lead author and assistant professor of neurosurgery at Tulane University School of Medicine, says, "We were interested in asking whether differences in infection experience could account, at least in part, for the differences in rates of dementia we see in the population. The mice we were studying were adults approaching middle age that had intact faculties, and yet, when exposed to intermittent inflammation, they remembered less and their neurons functioned more poorly."
To study the effect of this inflammation, the researchers used 10-month old male mice that were aging normally. Throughout their aging period, the animals were exposed to escalating doses of inflammation once every two weeks for 2.5 months. After this period, the researchers tested the mice's cognitive health and examined their brains, particularly the cerebral cortex and hippocampus.
The team says they did not find strong evidence of ongoing inflammation in the cerebral cortex or hippocampus, but they did observe impaired learning and memory, as well as disruptions to a hippocampal process thought to be linked to learning and memory.
The researchers say their findings suggest intermittent exposure to inflammation stemming from colds and flus leads to significantly impaired cognition in aging mice, which could have implications for older humans, as well.
Dr. Engler-Chiurazzi explains, "Our mice only experienced intermittent sickness-like inflammation a handful of times, so the fact that we observed impairments at all was surprising. The effects were subtle, but that's why I find these results meaningful: In a human, cognitive impairments from a similar number of inflammatory experiences might not be noticeable in their daily lives but could have cumulative effects that negatively impact the aging brain."
Though further research is needed to explore this link, the team says their findings should encourage people to try to avoid infections as much as possible.
One way to help could be getting your flu shot, which has been linked with a lower risk of dementia.
