Inflammation Markers Linked to Higher Risk of Cognitive Decline in Severe Gum Disease: Study

A recent study published in the Journal of Periodontology revealed that elevated inflammatory markers may signal a greater risk of cognitive decline, particularly among individuals with advanced periodontitis, thereby highlighting a potential connection between oral health and brain function.

The research examined 230 participants aged between 50 and 80 years, grouped into four categories as Alzheimer’s disease (52 individuals), mild cognitive impairment (51), subjective cognitive decline (51), and healthy controls (76). All participants underwent thorough oral examinations to assess signs of periodontitis, along with collection of saliva and blood samples. Cerebrospinal fluid (CSF) samples were also obtained from the patient groups to explore deeper biological changes.

This research measured key inflammatory markers like interleukin (IL)-1β, IL-8, IL-10, IL-17A, and tumor necrosis factor-alpha (TNF-α), in saliva, plasma, and CSF using advanced multiplex immunoassays. The goal was to identify whether the presence or severity of these markers correlated with both gum disease and cognitive impairment.

The study found the salivary levels of IL-1β, IL-10, and IL-17A to be markedly higher in individuals with mild cognitive impairment when compared to healthy controls. This suggests that inflammation originating in the mouth may emerge early in the trajectory of cognitive decline.

In blood plasma, IL-8 levels were consistently elevated across all 3 patient groups (subjective cognitive decline, mild cognitive impairment, and Alzheimer’s) when compared to the control group, with a highly significant association (p < 0.001). Plasma TNF-α levels were particularly high among participants with subjective cognitive decline and Alzheimer’s disease (p < 0.05), pointing to a systemic inflammatory response linked to worsening cognitive states.

Within the cerebrospinal fluid, IL-17A concentrations were higher in participants with no or only mild periodontitis than in those with generalized periodontitis (p = 0.023), which suggests complex inflammatory dynamics between oral and brain inflammation. The participants with severe gum disease displayed elevated IL-8 in both saliva (p = 0.027) and plasma (p < 0.001), along with higher plasma TNF-α (p = 0.041).

These findings collectively indicate that the severity of periodontitis correlates with stronger inflammatory responses across bodily systems, the responses that may, in turn, contribute to cognitive deterioration. Overall, the results highlight the potential of inflammatory biomarkers as early indicators of cognitive impairment and emphasize the importance of oral hygiene in preventing or slowing brain deterioration.

Source:

Buhlin, K., Eriksdotter, M., Jansson, L., Pussinen, P. J., Schultzberg, M., & Lira-Junior, R. (2025). The association of periodontal inflammation and inflammatory markers with cognitive dysfunction: A case-control study. Journal of Periodontology, jper.70020. https://doi.org/10.1002/jper.70020