Brushing your teeth properly could help keep more than 50 health conditions including dementia, rheumatoid arthritis and Parkinson's at bay, according to experts.
A panel at the world's largest general science conference have presented growing evidence that the spread of inflammation and infection caused by mouth bacteria is linked to problems throughout the body.
Researchers are only beginning to understand this relationship, they said, but it is clear that oral health can influence organs and tissues including the joints, brain and gut.
Alpdogan Kantarci, a professor of dentistry at the University of Minnesota, said advanced gum disease - called periodontitis - does not necessarily directly cause conditions such as dementia.
However, it may trigger common risk factors and accelerate disease in people who were already susceptible.
'Research is now showing that in people with mild or moderate diseases, those who are brushing and taking care of their teeth or seeing a dentist and having advanced cleanings, are showing much better cognitive responses,' he told the American Association for the Advancement of Science (AAAS) conference in Phoenix, Arizona.
'We now think that maintaining your teeth in health may be associated with a reduced risk of more than 50 systemic conditions.'
Professor Kantarci highlighted studies in mice which found periodontitis can increase brain inflammation, and that pathogenic oral bacteria can cross the blood-brain barrier, particularly in older mice.
Meanwhile, Dr Felipe Andrade, an associate professor of medicine at Johns Hopkins, presented evidence that pathogens responsible for gum disease also play a role in the development of rheumatoid arthritis.
And Dr Nobuhiko Kamada, from the University of Michigan's department of internal medicine, described how oral bacteria can influence the gut microbiome, potentially increasing the risk of inflammatory bowel disease and colorectal cancer.
Other conditions linked to oral health include heart disease, stroke and diabetes.
Professor Kantarci warned that sugary and ultra-processed diets are fuelling a sharp rise in tooth decay and gum disease.
He compared the UK to a third world country when it comes to oral care, adding that processed food, a soft diet and obesity are predisposing people to dental issues.
Figures from the Oral Health Survey for England show the prevalence of obvious tooth decay fell from 46 per cent to 28 per cent between 1998 and 2009.
However, the trend has now reversed -- the most recent 2023 survey found 41 per cent of adults with natural teeth had obvious tooth decay.
Some 93 per cent of people had at least one sign of periodontal disease, such as inflammation, tartar build-up or 'pocketing' between teeth and gums.
Professor Kantarci said the proliferation of food delivery services and processed foods has fuelled a shift away from natural eating and home cooking.
He added: 'This is affecting people's teeth, their oral health. So it's not a surprise that people are getting these diseases more in developed countries.'
'The answer is very clear - that we have to improve oral health awareness for systemic health.'
The dentist and gum surgeon is part of a taskforce of researchers working to calculate the economic and social benefits of improving people's oral health.
He urged health services and academics around the world to help raise awareness that good dental habits are vital not only for preventing cavities, but for reducing risk of many of the most feared conditions of old age.
The panel also called for international collaboration to better understand the relationship between different body systems.
Professor Kantarci advised people to brush their teeth two to three times a day, particularly after eating sticky or sugary foods. Those who can only brush once should do so before bed, he added.
For older people who may lack dexterity, he recommended using electric or motorised toothbrushes which can also be used to clean the tongue.