There is an increasing
body of evidence to indicate that gum (periodontal) disease could be a plausible risk factor for Alzheimer’s disease.
Some studies even suggest your risk doubles when gum disease persists for ten or more years. Indeed, a new US study published in
Science Advances details how a type of bacteria called Porphyromonas gingivalis – or P. gingivalis – which is associated with gum disease, has been found in the brains of patients with Alzheimer’s disease. Tests on mice also showed how the bug spread from their mouth to brain where it destroyed nerve cells.
The report in question was carried out and self-funded by founders of a US pharmaceutical company
Cortexyme, which is researching the cause of Alzheimer’s and other degenerative disorders. Scientists from the San Francisco drug firm will launch a human trial later this year.
What is gum disease?
The first phase of gum disease is called gingivitis. This occurs when the gums become inflamed in response to the accumulation of bacterial plaque on the surface of the teeth.
Gingivitis is experienced by up to half of all adults but is generally reversible. If gingivitis is left untreated, “sub-gingival pockets” form between the tooth and gum, which are filled by bacteria. These pockets indicate that gingivitis has converted to periodontitis. At this stage, it becomes almost impossible to eliminate the bacteria, though dental treatment can help control their growth.
The risks of gum disease are significantly increased in people with poor oral hygiene. And factors such as smoking, medication, genetics, food choices, puberty and pregnancy can all contribute towards the development of the condition.
Though it is important to remember that gum disease is not just the work of P. gingivalis alone. A group of organisms including Treponema denticola, Tanerella forsythia and other bacteria also play a role in this complex oral disease.
Mouth brain connection
At the University of Central Lancashire, we were the first
to make the connection with P. gingivalis and fully diagnosed Alzheimer’s disease.
Subsequent studies have also found this bacteria – which is responsible for many forms of gum disease – can migrate from the mouth to the brain in mice. And on entry to the brain, P. gingivalis can reproduce all of the characteristic features of Alzheimer’s disease.
The recent US research which found the bacteria of chronic gum disease in the brains of Alzheimer’s disease patients gives additional very strong research-based evidence – but it must be interpreted in context. And the fact of the matter is that Alzheimer’s disease is
linked with a number of other conditions and not just gum disease.