A high quality study conducted in Japan emphasised the importance of good dental care and treatment from an early age, for reducing the risk of dementia in later life.
This study of an elderly Japanese population indicated that subjects with greater tooth loss were at greater risk of onset of dementia. Losing teeth almost doubled the risk of developing the devastating neurological condition.
There may be several plausible reasons why tooth loss can cause dementia.
- It has been suggested that masticatory stimulation with normal occlusion (contact between teeth) increases cerebral blood flow, activation of the cortical area, and blood oxygen levels. Thus, poorer masticatory performance resulting from tooth loss might negatively affect brain function, which may result in development of dementia.
- Dietary changes resulting from tooth loss have been known to play a role in dementia risk. It was hypothesised that the decrease in masticatory performance due to tooth loss could lead to poor nutritional status, which might in turn affect dementia risk.
- The influence of chronic inflammation on development of dementia, especially in Alzheimer’s disease, is one possible pathway. Chronic systemic inflammation linked to periodontal disease, which is a major cause of tooth loss in adults, could contribute to the pathogenesis of Alzheimer’s disease.
- Finally, there is a possibility that poor oral health is a marker of overall health status, including potential risk factors for dementia, because common oral conditions such as tooth loss reflect history of diseases, health behaviour, and health care throughout the life course of an individual.