A Study of 500,000 Medical Records Links Viruses to Alzheimer’s Again And Again
January 3, 2024 | Source: Science Alert | by Felicity Nelson
A study of around 500,000 medical records suggested that severe viral infections like encephalitis and pneumonia increase the risk of neurodegenerative diseases like Parkinson’s and Alzheimer’s.
Researchers found 22 connections between viral infections and neurodegenerative conditions in the study of around 450,000 people.
People treated for a type of inflammation of the brain called viral encephalitis were 31 times more likely to develop Alzheimer’s disease. (For every 406 viral encephalitis cases, 24 went on to develop Alzheimer’s disease – around 6 percent.)
Those who were hospitalized with pneumonia after catching the flu seemed to be more susceptible to Alzheimer’s disease, dementia, Parkinson’s disease, and amyotrophic lateral sclerosis (ALS).
Intestinal infections and meningitis (both often caused by a virus), as well as the varicella-zoster virus, which causes shingles, were also implicated in the development of several neurodegenerative diseases.
The impact of viral infections on the brain persisted for up to 15 years in some cases. And there were no instances where exposure to viruses was protective.