Jan 31st 2019

Alzheimer’s is linked to gum disease – but bad oral health is not the only culprit

by Sim K. Singhrao

 

Senior Research Fellow in the School of Dentistry, University of Central Lancashire

 

For most people, teeth cleaning may just be a normal part of your daily routine. But what if the way you clean your teeth today, might affect your chances of getting Alzheimer’s disease in years to come?

There is an increasing body of evidence to indicate that gum (periodontal) disease could be a plausible risk factor for Alzheimer’s disease. Some studies even suggest your risk doubles when gum disease persists for ten or more years. Indeed, a new US study published in Science Advances details how a type of bacteria called Porphyromonas gingivalis – or P. gingivalis – which is associated with gum disease, has been found in the brains of patients with Alzheimer’s disease. Tests on mice also showed how the bug spread from their mouth to brain where it destroyed nerve cells.

The report in question was carried out and self-funded by founders of a US pharmaceutical company Cortexyme, which is researching the cause of Alzheimer’s and other degenerative disorders. Scientists from the San Francisco drug firm will launch a human trial later this year.

What is gum disease?

The first phase of gum disease is called gingivitis. This occurs when the gums become inflamed in response to the accumulation of bacterial plaque on the surface of the teeth.

Gingivitis is experienced by up to half of all adults but is generally reversible. If gingivitis is left untreated, “sub-gingival pockets” form between the tooth and gum, which are filled by bacteria. These pockets indicate that gingivitis has converted to periodontitis. At this stage, it becomes almost impossible to eliminate the bacteria, though dental treatment can help control their growth.

The risks of gum disease are significantly increased in people with poor oral hygiene. And factors such as smoking, medication, genetics, food choices, puberty and pregnancy can all contribute towards the development of the condition.

Though it is important to remember that gum disease is not just the work of P. gingivalis alone. A group of organisms including Treponema denticola, Tanerella forsythia and other bacteria also play a role in this complex oral disease.

Mouth brain connection

At the University of Central Lancashire, we were the first to make the connection with P. gingivalis and fully diagnosed Alzheimer’s disease. Subsequent studies have also found this bacteria – which is responsible for many forms of gum disease – can migrate from the mouth to the brain in mice. And on entry to the brain, P. gingivalis can reproduce all of the characteristic features of Alzheimer’s disease.

The recent US research which found the bacteria of chronic gum disease in the brains of Alzheimer’s disease patients gives additional very strong research-based evidence – but it must be interpreted in context. And the fact of the matter is that Alzheimer’s disease is linked with a number of other conditions and not just gum disease.

Existing research shows that other types of bacteria and the Herpes type I virus can also be found in Alzheimer’s disease brains. People with Down’s syndrome are also at a higher risk of developing Alzheimer’s disease, as are people who have had a severe head injury. Research also shows that several conditions associated with cardiovascular disease can increase the risk of Alzheimer’s disease. This suggests there are many causes with one endpoint – and scientists are still trying to figure out the connection.

This endpoint results in the same symptoms of Alzheimer’s: poor memory and behavioural changes. This also occurs alongside plaque buildup in the grey matter of the brain and what’s known as “neurofibrillary tangles”. These are the debris left from the collapse of a neuron’s internal skeleton. These occur when a protein can no longer perform its function of stabilising the cell structure.

Brush your teeth

The latest research adds more evidence to the theory that gum disease is one of the things that can lead to Alzheimer’s disease. But before you start panic brushing your teeth, it’s important to remember that not everyone who suffers from gum disease develops Alzheimer’s disease and not all who suffer from Alzheimer’s disease have gum disease.

To find out who is “at risk”, scientists now need to develop tests that can show the dentist who to target. Dental clinicians can then advise those people as to how they can reduce the risk of developing Alzheimer’s disease through better management of their oral health. But until then, regularly brushing your teeth and maintaining good oral hygeine is recommended.

 

Sim K. Singhrao, Senior Research Fellow in the School of Dentistry, University of Central Lancashire

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Browse articles by author

More Essays

Feb 1st 2018

There is a widespread perception that mental ill health is on the rise in the West, in tandem with a prolonged decline in collective well-being.

Jan 24th 2018

People over the age of 65 make up a larger percentage of the global population than ever before.

Jan 21st 2018

Donald Trump has been under constant fire from critics since he began his campaign in the summer of 2015, and his presidency has so far been perhaps the most chaotic and bizarre in recent decades.

Jan 17th 2018

PRINCETON – Last month, an Egyptian court sentenced Laura Plummer, a 33-year old English shop worker, to three years in prison for smuggling 320 doses of tramadol into the country. Tramadol is a prescription opioid available in the United Kingdom for pain relief.

Jan 9th 2018

Two American academics who lost relatives in the liquidation of Western Ukrainian political prisoners in World War II have compiled the first exhaustive account of this little-known Soviet killing spree. What happened?

Jan 9th 2018

When people experience stress, the adrenal glands that sit on top of the kidneys release a steroid hormone called cortisol.

Jan 7th 2018

It’s January, so it’s likely that you have set yourself goals to be more physically active and less stressed in 2018. Paradoxically, better goals would be to stop worrying about how much exercise you’re getting and to stop worrying about being too stressed.

Jan 6th 2018
Paul Valéry met Edgar Degas in 1896, and the two were friends for the two decades that remained in Degas’ life – the poet, almost 30 years younger, was in awe of the older painter, whom he considered a genius, and the painter was clearly flattered by the interest of the brilliant young poet. Valéry early had the idea of writing a book about Degas, but Degas was too cantankerous to agree to the project. In the event it was not until 20 years after Degas’ death that Valéry published his reflections and recollections in a small book he titled Degas Dance Dessin. Now, on the hundredth anniversary of Degas’ death the Musee D'Orsay honors the painter with an exhibition of his art seen through the lens of his relationship with Valéry, and the themes of the poet's book.
Jan 4th 2018

Whether you get mesmerised by Vincent van Gogh’s painting The Starry Night or Albert Einstein’s theories about spacetime, you’ll probably agree that both pieces of work are products of mindblowing creativity.

Jan 3rd 2018

Ever since we learned that eighty percent of self-described "born-again" Christians supported Donald Trump's candidacy for president, there has been a discussion about how these Christians define their faith.

Dec 17th 2017

Happiness is the subject of countless quotations, slogans, self-help books and personal choices.

Dec 12th 2017

President Trump’s announcement on Wednesday, Dec. 6 that the U.S. would recognize Jerusalem as the capital of Israel received widespread criticism.

Dec 8th 2017

In the wake of the deluge of news about sexual harassment and alleged assaults by several high-profile and powerful men, it is important to look at the causes and consequences of forced sex in the workplace – but also in intimate relationships.

Dec 5th 2017

A place of spacious dimensions, and large population, with fine bazaars. It contains numerous mosques, and there is no wall around it.

Nov 29th 2017

The announcement that Prince Harry is set to marry American actress Meghan Markle provoked a flurry of articles about the British royal family becoming multicultural.

Nov 29th 2017

People discuss their problems with friends in the hope that they’ll gain some insight into how to solve them. And even if they don’t find a way to solve their problems, it feels good to let off some steam. Indeed, having close friends to confide in is a good buffer against poor mental health.

Nov 23rd 2017

Everyone knows what it feels like to have consciousness: it’s that self-evident sense of personal awareness, which gives us a feeling of ownership and control over the thoughts, emotions and experiences that we have every day.

Nov 21st 2017

Paul Cézanne painted his uncle Dominique Aubert at least 9 times in 1866, when the artist was 27 years old.

Nov 20th 2017

MILAN, Italy – The ambitiously conceived exhibition 'Dentro Caravaggio' (Inside Caravaggio) wants us to see this extraordinary painter with new eyes.