Could Good Oral Health Prevent Dementia?

Connection Between Periodontal Disease and Alzheimer's Disease

Periodontitis is a lifelong, highly prevalent, chronic inflammatory disease associated with stroke, cardiovascular disease, systemic inflammation and endothelial dysfunction.

A new study by Noble et al published in the Journal of Neurology, Neurosurgery and Psychiatry suggests there may also be a relationship between periodontal disease and dementia.

Dementia is a major public health problem likely related to a complex interaction between genetics, smoking and diseases associated with systemic inflammation, including  diabetes and stroke. These risk factors have a similar systemic inflammatory profile to periodontitis which suggests that they may also provide a common pathway of atherogenesis related to systemic inflammation.

In a study of 2,355 people aged 60 years and older, Noble et al reported an association between a common periodontal pathogen, Porphyromonas gingivalis, and cognitive impairment. The researchers found individuals with high levels of P. gingivalis had 200 percent increased incidence of impaired verbal memory and subtraction test performance. This association adds to a growing body of evidence for a relationship between poor oral health and dementia.

Oral health problems including periodontal disease, caries, edentulism and inadequate preventive care are more prevalent with increasing age resulting in increased exposure to periodontal pathogens.

One possible reason is a decreased ability to perform plaque control due to arthritis and other physical impairments. Exposure to periodontal pathogens is ubiquitous in older adults who often suffer from arthritis and thus have more difficulty keeping their mouths healthy.

Furthermore, cognitive function is thought to be associated with nutrition. Loss of teeth in older adults may be associated with poor nutrition. Consequently, there may be a relationship between loss of teeth and artherosclerotic changes.

Could Good Oral Health Prevent Dementia?

In an editorial commentary, Dr. Robert Stewart at the Institute of Psychiatry Kings College London, notes the oral health of people with cognitive impairment should, at the very least, receive more clinical attention.  He adds: "If there are good reasons to suspect a link between oral health and cognition, why has this received so little attention to date? The obvious but rather prosaic reason is the historic separation between medicine and dentistry. Clinical specialists have long been a hindrance to effective research (an example being the lack of attention paid to the vascular etiology of dementia) and it is about time that we accepted that disorders do not necessarily follow the way we structure our professions."