8th March 2017 – Losing teeth when you're older may indicate a risk of dementia, say scientists.
A Japanese study has found that people who retain the most teeth over the age of 60 are least likely to develop dementia. However, dementia risk seems to increase in line with the number of teeth lost after this age, say researchers.
The researchers found that the risk of developing dementia rose by 62% for those with 10 to 19 remaining teeth compared to those with 20 or more of their original set of 32.
This extra risk rose to 81% for those who had between 1 and 9 teeth left.
Tooth loss was seen to be linked to the development of Alzheimer's disease but not to that of vascular dementia, although the researchers point out that there were fewer cases of vascular dementia to draw data from.
Inflammation or unhealthy habits
The team put forward explanations for why dementia and tooth loss might be related. They say that chewing may increase blood flow and boost oxygen levels in the blood, whereas people with few teeth might find this harder to do. Also, a lack of teeth might make it harder for people to eat healthily.
Another possible explanation is that tooth decay and gum disease could trigger inflammation – a risk factor for Alzheimer's disease.
Finally, tooth loss might reflect a general lack of care and healthy habits throughout an individual's life, they say.
The authors of the study, in the Journal of the American Geriatrics Society, conclude: "The findings emphasise the clinical importance of promoting and supporting opportunities for dental care and treatment, especially in terms of maintenance of teeth from an early age for reducing the risk of dementia in later life."
Lowering the risk of dementia
In an emailed comment, Dr Rosa Sancho, head of research at Alzheimer's Research UK, says: "Understanding how lifestyle factors can affect our risk of developing dementia is important, as there may be simple changes we can make to reduce our risk. This new study focuses on a potential link between oral health and dementia risk, finding that people with fewer teeth had an increased risk of developing dementia.
"This study didn’t look at the mechanisms underlying the link between oral health and dementia, but some research suggests that gum disease can raise the level of inflammation in the body and may contribute to a person’s dementia risk. Research is increasingly focussing on how inflammation plays a role in dementia, and this knowledge will help to influence our understanding of the risk factors for the condition."
"Good dental care is an important part of a healthy lifestyle, but we do not know the extent to which it can affect our dementia risk. The current best evidence for reducing our risk of dementia is that what is good for the heart is good for the head. Not smoking, eating a healthy balanced diet, keeping physically active, drinking in moderation, keeping cholesterol and blood pressure in check, and maintaining a healthy weight are all ways we can reduce our risk of dementia."
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