Researchers in Japan have found that people with fewer teeth had an increased risk of developing dementia, indicating that oral health may be a risk factor for dementia. The study is published today (8 March) in The Journal of the American Geriatrics Society.
The study involved people who are part of the Hisayama Study, a population-based study of people living in the town of Hisayama in Japan. In 2007 and 2008, 1,566 people underwent a dental examination during which their number of teeth was recorded. People were categorised into four groups based on how many teeth they had – 20 or more teeth, 10-19 teeth, 1-9 teeth or no teeth. The groups were then followed for 5 years and assessed for the development of memory problems and dementia.
During the 5 years of follow up, 180 people developed dementia of which 127 people were diagnosed with Alzheimer’s disease and 42 people with vascular dementia. Compared to people with 20 or more teeth, those with 10-19 teeth had a 62% increased risk of developing dementia, those with 1-9 teeth an 81% increased risk and those with no teeth a 63% increased risk. The association between tooth loss and dementia remained even when the researchers adjusted for other factors, including age, education, high blood pressure, alcohol intake and diabetes.
Dr Rosa Sancho, Head of Research at Alzheimer’s Research UK, said:
“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.”