Infections Can Exacerbate Memory Loss in Alzheimer’s

A new study suggests that having an inflammatory condition like a cold or urinary infection can hasten memory loss in people with Alzheimer’s. It was done by physicians in UK, and it’s published in the journal Neurology.

222 patients with mild to moderate Alzheimer’s disease had cognitive testing and provided blood for determination of levels of the inflammatory ‘marker’, tumor necrosis factor-alpha (TNF-alpha). Patients’ caregivers were asked to record any recent infectious illnesses or inflammatory injuries.  All these assessments were repeated after 2, 4, and 6 months.

About half the patients had at least one inflammatory condition during the study, and these episodes were associated with an increase in TNF-alpha levels, as well as twice the rate of cognitive decline seen in the other patients.  High baseline levels of TNF-alpha (indicating a chronic inflammatory condition) were associated with a 4-fold increase in the rate of cognitive decline.  Patients who had a low baseline level of TNF-alpha throughout had no cognitive decline during the study.

These results are a new, promising line of research to be followed in our attempts to learn more about the causation of Alzheimer’s. They also suggest that older people, especially those with Alzheimer’s or other forms of dementia, should treat all infections seriously. It’s possible that keeping inflammation (and inflammatory markers like TNF-alpha) at low levels will delay the inevitable cognitive decline seen in dementias.