Oral hygiene habits are inculcated from an early age – we should brush our teeth twice a day and ideally floss. The reasons given (from avoiding bad breath to the threat of a painful visit to the dentist) make for a pretty compelling argument.
Despite this, the nation’s oral health is not in good shape. Gingivitis – the precursor to gingivitis – affects most adults in the UK to some extent at some point, while one study found that only 17 per cent of UK adults did not have any sign of gum disease; And the consequences can be more significant than a bleeding gum or a steep dentist bill.
Alzheimer’s is the most common cause of dementia and accounts for about six out of every 10 cases of dementia. It was the leading cause of death in the UK in 2022 and affects around 940,000 people in the UK. This number is expected to rise to over one million by 2030.
There are many lifestyle behaviors that are thought to increase the risk of Alzheimer’s, including smoking, drinking, high blood pressure, and high cholesterol. And there is growing strong evidence that a possible cause of Alzheimer’s disease development can be found in unhealthy gums.
Jing Kang is a senior lecturer in medical statistics at King’s College London and researches the link between oral health and Alzheimer’s. He says there seems to be a two-way relationship between our mouths and our brains.
On the one hand, maintaining good oral health can be a significant challenge for people with Alzheimer’s, with dementia inadvertently leading to gum disease and tooth loss. And on the other hand, he says, “gum disease or painful, bleeding gums has been linked to a greater likelihood of developing dementia. There is scientific evidence that shows a type of bacteria commonly found in people with gingivitis (Porphyromanos gingivalis), was recently found in the brains of Alzheimer’s patients.”
If you don’t take care of your teeth, the small gap between the tooth and the gums can widen as bacteria builds up. This causes increasing inflammation, eventually leading the gums to pull further away from the tooth. And in that gap, it’s believed that bacteria can enter our bloodstream, eventually traveling to the brain and perhaps wreaking havoc.
Alzheimer’s involves the buildup of misfolded proteins called amyloid plaques, which are associated with cell death and cognitive decline. There are specific cells responsible for fighting amyloid plaque, but the bacteria in gum disease seem to inhibit the ability to do so. “Brain damage may be caused by gum bacteria and possibly linked to memory loss or cognitive decline,” Kang adds. “As it accumulates over time, it could lead to the onset of dementia.”
Different studies have found other connections between periodontitis and Alzheimer’s. A found that people with fewer than 10 teeth have a smaller area of the brain critical for memory, suggesting that tooth loss may precede the development of dementia. And studies have reported a lower chance of people developing Alzheimer’s disease when patients with frequent gingivitis were treated for an oral infection, although their risk would increase if they exceeded four extractions. This suggests that chronic inflammation particularly increases Alzheimer’s risk.
Kang also points to additional studies where people with gingivitis are treated and then their cognitive function is measured years later. “Some have shown a slower rate of cognitive decline compared to people with gingivitis who did not receive treatment. The scale of the study is quite small (these kinds of clinical studies take a long time and are very expensive), but there is data and evidence showing that treating gum disease at an early stage reduces the rate of cognitive decline.”
More data is needed to say definitively that taking care of your oral health can prevent dementia. But scientists, including Kang, think protecting your oral health as a preventative measure is a very good idea.
“People are still investigating how it works biologically, but if we say our hypothesis is that bacteria from the mouth can penetrate the gums and travel throughout the body and reach parts of the brain, then preventing bacteria from entering in the gums by maintaining Good hygiene would reduce the risk of dementia later in life.’
In addition, there is a risk of other chronic, degenerative or even fatal diseases if you do not take care of your oral health. Gingivitis may increase the risk Diabetes, rheumatoid arthritis, heart disease and respiratory diseases.
How to stop gum disease
“Prevention is key when it comes to reducing the chance of Porphyromonas gingivalis bacteria growing inside the oral cavities,” explains Dr. Smita Mehra, Principal Dentist at The Neem Tree Dental Practice.
This means going for regular dental checkups and trips to the hygienist, as well as developing consistent oral hygiene habits. “Small steps like brushing your teeth twice a day, regular dental checkups, flossing, and treating gum disease as early as possible will make a huge difference later in life,” Kang adds.
This will also help reduce the number of tooth extractions, which could be instrumental in preventing the development of Alzheimer’s.
“Clinicians need to have conversations with patients about the benefits of good oral hygiene practices and the importance of retaining as many natural teeth as possible as they age,” explains Shalini Kanagasingam, specialist endodontist and clinical lecturer at the University of Central Lancashire .
