Oral Health and Brain Health: How Gum Disease May Fuel Alzheimer’s
Over 60% of adults over age 65 live with periodontitis—a chronic inflammatory disease that damages the gums and bone supporting the teeth. At the same time, Alzheimer's disease (AD), the most common form of dementia, affects approximately 55 million people worldwide. Recent research has begun to explore an intriguing connection: could the health of your gums impact your brain?
Gum Disease and Inflammation: A Systemic Problem
Periodontitis isn’t just a mouth issue—it triggers systemic inflammation. This chronic infection can elevate inflammatory markers like IL-1α, IL-6, TNF-α, and C-reactive protein (CRP) in the bloodstream. These same markers are linked with the brain changes seen in Alzheimer’s, including the buildup of amyloid-beta proteins and tau tangles.
Controlling gum inflammation may help reduce overall inflammation in the body, which could play a role in slowing down neurodegeneration.
How Oral Bacteria Reach the Brain
One key suspect in the gum-brain connection is Porphyromonas gingivalis (Pg), a harmful oral bacteria involved in periodontitis. Pg and its toxic enzymes, called gingipains, have been detected in the brain tissue and spinal fluid of Alzheimer’s patients. One study found Pg DNA in the brains of 51 out of 53 patients with AD during autopsy.
In animal studies, oral infection with Pg led to colonization of the brain, increased amyloid buildup, and signs of cognitive decline. Interestingly, the use of gingipain inhibitors helped reduce these effects.
How Does It Happen?
Researchers believe oral pathogens may reach the brain in a few ways:
Through the bloodstream: Inflammation can weaken the blood-brain barrier, allowing bacteria and toxins to enter the brain.
Through cranial nerves: Pg may travel along the trigeminal nerve directly into brain tissue.
By triggering immune reactions: Bacterial toxins can activate enzymes in the brain that lead to plaque formation and cell damage.
Real-World Evidence
A six-month study of people living with Alzheimer’s found that those with untreated periodontitis experienced cognitive decline six times faster than those with healthy gums. Other studies have shown that AD patients tend to have worse periodontal health, higher levels of inflammatory markers, and more antibodies against oral bacteria.
Can Treating Gum Disease Help?
While we don’t yet have large-scale clinical trials confirming that treating gum disease can prevent Alzheimer’s, early studies in animals are promising. Treatments like curcumin (an anti-inflammatory) and gingipain inhibitors have reduced neuroinflammation and improved memory in mice.
What this tells us is simple: caring for your gums may do more than protect your smile—it might also protect your brain.
Final Thoughts
Although we can’t say for sure that gum disease causes Alzheimer’s, there is strong evidence suggesting a connection. Chronic inflammation, harmful bacteria, and immune responses seem to link the two. Maintaining good oral hygiene and seeking regular dental care may be a low-risk, high-reward step in protecting your overall health as you age.
Discussion Prompt
Have you ever considered how your oral health could affect your memory or brain health? Would knowing this connection change how you prioritize dental care?
Sources:Centers for Disease Control and Prevention. (2021).Chen et al. (2025). Oral Diseases.Dominy et al. (2019). Science Advances.Ide et al. (2016). PLOS One.Pelc, S. (2022). Dimensions of Dental Hygiene.Sarmiento-Ordoñez et al. (2025). Journal of Alzheimer’s Research.Perio.org. (n.d.).MDPI (2023). Journal of Clinical Medicine.Fu et al. (2023). Oral Diseases.
