People with gum disease may be at increased risk of dementia, according to a new study. .

It revealed people with poor oral health also have higher amyloid beta levels, a dangerous protein found in the brain of Alzheimer's sufferers.  .

But while a link has been firmly established between the protein and dementia, exactly how beta amyloid causes the disease remains only partially understood.

People in this age group are at increased risk of both dementia and gum disease, with 70 per cent of over-65s suffering from the oral condition.  

It revealed people with poor oral health also have higher amyloid beta levels, a protein found in the brain of Alzheimer's sufferers

Bacteria balance for all 48 people was compared to levels of beta amyloid and tau, another protein known to be present in dementia patients. 

Data shows that individuals with more good bacteria than bad bacteria in their gums had lower levels of amyloid in their cerebrospinal fluid, indicating they are less at risk of dementia.  

'Our results show the importance of the overall oral microbiome - not only of the role of 'bad' bacteria, but also 'good' bacteria - in modulating amyloid levels,' said Dr Kamer. 

As a result they are unable to say whether tau lesions will develop in the people with high amyloid levels, or if they will in fact go on o develop Alzheimer's. 

The researchers are now setting up a clinical trial to investigate if improving gum health with deep cleans can modify brain amyloid and prevent Alzheimer's disease

Analysis also revealed married people who participate in a pastime or hobby are 30 per cent less at risk of dementia