29 Early Warning Signs of Dementia You Can Manage

New research from a nationwide registry study in Finland has identified 29 diseases and infections that appear in the years preceding a dementia diagnosis and are linked to a higher risk of cognitive decline. The findings, published in PLOS Medicine, suggest that certain severe infections may independently increase the risk of developing dementia, even when other contributing health conditions are taken into account.

The study analyzed data from 62,555 participants with dementia and 312,772 controls, with an average participant age of 81 years. Researchers focused on individuals aged 65 or older who experienced late-onset dementia between 2017 and 2020. To identify patterns, the team reviewed hospital inpatient and outpatient records to track diagnoses occurring one to 21 years prior to the dementia diagnosis.

The Role of Severe Infections

A primary focus of the research was to determine if severe infections—defined as those requiring hospital treatment—independently raise dementia risk. While many chronic conditions are known to correlate with cognitive decline, the Finnish study sought to disentangle these factors to see if infections played a distinct role.

Among the 29 identified conditions, two specific types of infection stood out. Participants experienced cystitis an average of six and a half years before their dementia diagnosis. Bacterial infections of an unspecified site occurred an average of just over five and a half years before diagnosis.

The researchers noted that while other conditions may increase the likelihood of developing these infections—identifying 19 conditions linked to cystitis and 10 linked to unspecified bacterial infections—the infections themselves still appeared to increase the risk for dementia after adjusting for those prior diseases.

Other Linked Conditions

Beyond infections, the study identified other medical conditions strongly associated with a subsequent dementia diagnosis. Among the most prominent were Parkinson’s disease and mental disorders resulting from brain damage.

The research indicates that the trajectory of these 29 diseases often begins years before the onset of cognitive symptoms, providing a potential window for medical observation and intervention.

Understanding the Implications

The identification of these 29 conditions highlights the complex interplay between systemic health and brain function. Because many of these conditions are treatable or manageable, identifying them early may allow for better health management that could potentially mitigate overall risk.

However, the researchers emphasize that dementia risk is multifactorial. While these 29 conditions are linked to a higher risk, they are not the sole cause, and the relationship between specific infections and cognitive decline remains an area of ongoing investigation.

The study’s use of a nationwide registry allowed for an extensive dataset, which helped researchers account for various comorbidities that often cloud the relationship between a single infection and the eventual development of dementia.