Scientists discover Alzheimer’s cause could actually come from inside your mouth

Alzheimer’s disease has long puzzled scientists, with its exact cause remaining unclear. Traditionally, researchers have focused on factors such as genetics, aging, and environmental influences. However, some experts suggest that a key trigger for the disease may have been overlooked—oral health.

A Surprising Link Between Gum Disease and Brain Health

In 2019, a study proposed that periodontitis, commonly known as gum disease, may play a role in the development and progression of Alzheimer’s disease. Researchers found that Porphyromonas gingivalis, the bacteria responsible for chronic gum disease, was present in the brains of deceased Alzheimer’s patients.

This discovery, supported by University of Louisville microbiologist Jan Potempa, suggested a potential oral-brain connection that had previously been underestimated.

Could gum disease be linked to Alzheimer’s (Peter Dazeley/Getty)

How Could Oral Bacteria Affect the Brain?

The symptoms of Alzheimer’s typically appear when parts of the brain begin to shrink, a process called atrophy. The NHS states that this can disrupt memory, thinking, and cognitive function. While age, lifestyle, and genetics have traditionally been linked to this shrinkage, the 2019 study suggested an alternative factor: oral infections.

Prior experiments involving mice showed that an oral infection with P. gingivalis led to the bacteria colonizing the brain. Additionally, these infections were associated with an increase in amyloid beta proteins, a key marker of Alzheimer’s disease.

Groundbreaking but Not Definitive

Although this research presents compelling evidence, scientists haven’t confirmed whether gum disease directly causes Alzheimer’s or if cognitive decline leads to poor oral health.

Stephen Dominy, co-founder of the pharmaceutical startup Cortexyme, which led the study, acknowledged this uncertainty:

“Infectious agents have been implicated in the development and progression of Alzheimer’s disease before, but the evidence of causation hasn’t been convincing. Now, for the first time, we have solid evidence connecting the intracellular, Gram-negative pathogen, P. gingivalis, and Alzheimer’s pathogenesis.”

The study also found toxic enzymes called gingipains—secreted by P. gingivalis—in the brains of both Alzheimer’s patients and individuals who had not been diagnosed with the disease, further deepening the mystery.

What This Means for Future Research

While scientists continue to investigate, these findings highlight the importance of oral hygiene and its potential impact on brain health. As research advances, understanding the role of gum disease in Alzheimer’s could lead to new prevention and treatment strategies.

For now, one thing is clear—taking care of your oral health might be more important than we ever imagined.

Featured Image Credit: Getty Stock Images