Each year, neurodegenerative diseases that cause brain cell death are responsible for nearly two million deaths worldwide. Alzheimer’s disease, the most common form of dementia, is typically diagnosed in people over 65 and progresses in stages, gradually destroying cognitive abilities.
An international team of scientists from the National University of Singapore, led by Wei Yuy Chua and Eng-King Tan, conducted a large-scale analysis to determine how severe infections requiring hospitalization influence the likelihood of developing dementia. The study included data from more than four million patients from countries such as the United Kingdom, United States, Finland, Taiwan, New Zealand, and various European nations.
The results are alarming: people who had infectious diseases severe enough to require hospitalization faced an 83% higher risk of developing any type of dementia compared to those who were not hospitalized for infection. The impact was particularly pronounced for sepsis, pneumonia, urinary tract infections, as well as skin and soft tissue infections.
How different infections affect the brain
Sepsis increased the risk of dementia by 78%, pneumonia by 69%, urinary tract infections by 57%, and skin and soft tissue infections by 42%. Notably, patients who had suffered a severe infection were nearly four times as likely to develop vascular dementia, and the risk of Alzheimer’s disease rose by one and a half times.
Scientists explain this by pointing out that infectious processes cause inflammation and damage to blood vessels, disrupting the protective barrier between the blood and brain. As a result, inflammatory molecules and pathogens can penetrate brain tissue, accelerating the accumulation of proteins associated with Alzheimer’s disease. In cases of vascular dementia, infection damages small vessels, leading to reduced blood supply to the brain.
The first months after hospitalization are a critical period
Researchers recommend paying special attention to patients over 60 who have suffered from severe infections. The highest risk of cognitive impairment is observed within the first year after being discharged from the hospital. During this time, it is important to regularly monitor memory and thinking skills to promptly detect possible changes.
To reduce the likelihood of developing dementia, experts recommend implementing early cognitive monitoring programs, controlling inflammation, maintaining cardiovascular health, and getting timely vaccinations against respiratory infections.
Prevention and long-term consequences
The effects of past infections can persist for many years, making prevention a key factor in combating dementia. Doctors emphasize that infectious diseases should not be seen as merely a temporary ailment—they can accelerate brain aging and trigger irreversible processes.
Timely detection of cognitive impairments and a comprehensive approach to treating infections can reduce risks for elderly patients. It’s important to remember that even after a full recovery from an infection, the brain may remain vulnerable to developing neurodegenerative changes.
By the way: Who are Wei Yu Chua and Eng-King Tan
For reference, Wei Yu Chua and Eng-King Tan are leading experts in neurology and neurodegenerative diseases. Both scientists work at the National University of Singapore, one of Asia’s largest research centers. Eng-King Tan is renowned for his work on brain aging mechanisms and dementia prevention. Under his guidance, major international projects have been carried out to advance early diagnosis of Alzheimer’s disease. Wei Yu Chua specializes in the analysis of large-scale medical data and the development of new methods for monitoring cognitive health. Their collaborative research has been repeatedly recognized by the scientific community and acclaimed at international conferences. Thanks to their contributions, approaches to the prevention and treatment of dementia are becoming more effective and scientifically grounded.
