A new large-scale study has found that being hospitalized with an infection can significantly raise the risk of developing dementia later in life.
This discovery is especially important as people live longer and more hospital visits occur due to infections. It may also offer new ways to think about how to prevent dementia.
The study was led by researchers from the National University of Singapore, the National Neuroscience Institute, and Duke-NUS Medical School. It was published in the journal Aging.
The team reviewed data from over 4 million people across 16 different studies, making it the most complete review so far on how infections in hospitals might be linked to long-term brain health.
The results showed that people who were hospitalized for any kind of infection had an 83% higher risk of developing dementia later on. This included infections such as sepsis, pneumonia, urinary tract infections, and skin infections.
Among these, sepsis carried the highest risk. Vascular dementia—a type caused by problems with blood flow in the brain—was more strongly linked to infections than Alzheimer’s disease.
So why would infections raise the risk of dementia? One explanation is that infections can cause widespread inflammation in the body. This inflammation may reach the brain and damage it.
When the immune system fights off an infection, it produces chemicals that help fight germs. But in some cases, these same chemicals can harm healthy brain cells or allow harmful proteins to build up in the brain. This damage might happen more easily in older adults, whose immune systems are slower and weaker.
The study also found that even one hospital stay for an infection could make memory and thinking problems worse, especially for people already at risk for dementia. The risk of dementia was highest in the first year after the infection, but it remained high for many years.
In fact, studies that followed people for more than 10 years showed an even stronger link between infections and dementia. This means the effects of an infection can last a long time.
These findings suggest that doctors should closely watch the brain health of older adults after they leave the hospital following an infection. Checking memory and thinking skills early may help find problems before they get worse. This is especially important for people who already have risk factors for dementia.
This study also sends a strong message to health systems around the world. More than 50 million people currently live with dementia, and the cost of care in the United States alone is more than $300 billion each year.
That’s why finding new and preventable causes of dementia is so important. Preventing infections, improving hospital care, and supporting patients after they recover could help protect their brain health.
In conclusion, this research shows that infections may do more than make people sick in the short term. They could also raise the risk of long-term brain problems. For older adults, a hospital stay for an infection should not be taken lightly.
It’s a signal to keep a closer eye on brain health, and it offers doctors a chance to step in early. Reducing infections and tracking cognitive health after illness may turn out to be powerful tools in the fight against dementia.
If you care about brain health, please read studies about Vitamin B9 deficiency linked to higher dementia risk, and cranberries could help boost memory.
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