In surprising findings, recent research has linked vaccines to lower dementia risk. Another recent study may help explain why this connection exists. Researchers found that severe infections may increase dementia risk years later. The findings suggest that preventing infections could help protect brain health.
The study included more than 62,000 older adults. Researchers recruited participants in 2016 and followed them through 2021. Participants were at least 65 years old when the study began. The average participant age was approximately 81 years old.
What Are the Findings?
Researchers compared participants diagnosed with dementia against a large control group. Nearly 313,000 control participants did not develop dementia during the same period. After analyzing the data, researchers identified 29 medical conditions associated with later dementia diagnosis. These conditions were diagnosed between one and 21 years before dementia appeared.
Importantly, the results remained significant even after accounting for other illnesses. Researchers found that dementia was much more common among participants with these conditions. The conditions covered a broad range of health problems. These included injuries, mental disorders, cardiovascular disease, neurological conditions, and endocrine disorders.
Among all participants, 47 percent experienced at least one linked condition. More than 20 percent developed two associated conditions. Some of the most common conditions included ischemic stroke, traumatic brain injury, and type 2 diabetes. However, not every condition carried the same level of risk.
Mental disorders showed some of the strongest associations with dementia. Researchers believe this may result from physical brain damage or other neurological changes. Parkinson’s disease and alcohol-related mental disorders also demonstrated particularly strong connections. Depending on the condition, diagnoses typically occurred five to 12 years before dementia developed.
Researchers also examined severe infections requiring hospital treatment. More than 65 percent of the studied diseases showed links to increased infection risk. Urinary tract infections, or UTIs, appeared especially important. Strong associations were found between UTI risk and conditions such as epilepsy, hemorrhagic stroke, and alcohol-related disorders.
What’s Next?
Scientists proposed several explanations for the connection between infections and dementia. One possibility involves inflammation triggered by severe infections. Other theories include immune system communication problems and harmful substances circulating in the blood. Researchers suggest these processes may gradually affect the brain over time.
Importantly, the findings do not suggest that infections directly cause dementia in most cases. Instead, severe infections may help create conditions that allow dementia to develop. Researchers describe this process as contributing to preclinical dementia. In other words, the disease process may begin long before symptoms appear.
To strengthen their findings, researchers analyzed participants by sex and education level. The associations remained consistent across these groups. However, the team acknowledged limitations. Some lifestyle behaviors and other factors could not be fully measured.
Dementia is typically diagnosed after age 80. Many older adults also have medical conditions that increase infection risk. Researchers believe their findings highlight the importance of preventing and treating serious infections. While the results are compelling, further studies are needed to determine whether prevention, treatment, or both offer the greatest protection against dementia.
Conclusion
Researchers found that severe infections may increase dementia risk years later. The findings suggest that infection-related inflammation could help create conditions that allow dementia to develop. More research is needed, but preventing and treating serious infections may help protect long-term brain health.
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Logan Hamilton is a health and wellness freelance writer for hire. He’s passionate about crafting crystal-clear, captivating, and credible content that elevates brands and establishes trust. When not writing, Logan can be found hiking, sticking his nose in bizarre books, or playing drums in a local rock band. Find him at loganjameshamilton.com.
