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

Oct 18th 2018
Leaving a major political body is nothing new for mainland Britain. In 409AD, more than 350 years after the Roman conquest of 43AD, the island slipped from the control of the Roman Empire. Much like the present Brexit, the process of this secession and its practical impacts on Britain’s population in the early years of the 5th century remain ill-defined. As with the UK and Brussels, Britain had always been a mixed blessing for Rome. In around 415AD, St Jerome called the island “fertile in tyrants” (meaning usurpers) and late Roman writers portrayed a succession of rebellions in Britain, usually instigated by the army – many of whom would have been born in the province.
Oct 16th 2018
One of the oldest Greek myths, the story of Pandora was first recorded more than 2,500 years ago, in the time of Homer. In the original telling, Pandora was not some innocent girl who succumbed to the temptation to open a forbidden jar......Pandora was deliberately devised to punish humankind for accepting the gift of fire from Prometheus. Essentially a seductive AI fembot, she had no parents, childhood memories, or emotions of any kind, nor would she ever age or die. She was programmed to carry out one malevolent mission: to insinuate herself in an earthly setting and then unseal the jar......With AI/machine learning quickly evolving into a “black box” technology, the symbol of Pandora’s sealed jar has taken on new meaning.
Oct 11th 2018
The Scottish National Gallery in Edinburgh is currently exhibiting a substantial selection of Rembrandt’s paintings, drawings, and prints – focusing on those works that reveal the story of “Britain’s Discovery of the Master.” Exploring the significance of Rembrandt to British collectors, artists, and writers provides us with the occasion to revisit some fifteen major oil paintings.....
Oct 10th 2018
On the fiftieth anniversary of Nicolas Garcia Uriburu’s first coloration, Buenos Aires’ National Museum of Fine Arts pays tribute to the landmark early accomplishment of its native son..........Uriburu’s role as an early environmentalist has never been appreciated outside of his native country. It is sad that this neglect was not remedied in his lifetime, but at least it should be done now; a full-scale retrospective of his pioneering work should be presented in the art world’s capitals, to inspire young artists.
Oct 2nd 2018
The 2018 Nobel Prize in Physiology or Medicine has been awarded to two immunologists for their revolutionary approaches to treat cancer. James Allison, based in the MD Anderson Cancer Center in Houston, Texas, and Tasuku Honjo, based at Kyoto University in Japan, led exciting and groundbreaking work on developing new types of immunotherapy that help our immune system fight cancer.
Sep 20th 2018
We all want other people to “get us” and appreciate us for who we really are. In striving to achieve such relationships, we typically assume that there is a “real me”. But how do we actually know who we are? It may seem simple – we are a product of our life experiences, which we can be easily accessed through our memories of the past. Indeed, substantial research has shown that memories shape a person’s identity......................But it turns out that identity is often not a truthful representation of who we are anyway – even if we have an intact memory. Research shows that we don’t actually access and use all available memories when creating personal narratives. It is becoming increasingly clear that, at any given moment, we unawarely tend to choose and pick what to remember.
Sep 20th 2018
The research, published in the Canadian Medical Association Journal, compared how much mothers reported using cleaning products with the rate of obesity in 757 children at the age of three. Faecal samples were taken from the infants at three to four-months-old and the researchers investigated associations between microbial changes and being overweight at age three. The researchers found a link between heavy use of cleaning products, microbial changes and children with a higher body mass index (BMI). However, higher disinfectant usage was also reported among households with infants who received antibiotics around the time of birth; who were exposed to cigarette smoke; or were delivered by caesarean section. The results may therefore reflect several interlinking factors. Obesity was less likely to occur in breastfed children, but breastfeeding was also linked to lower disinfectant usage, which makes it difficult to tease apart these two factors.
Sep 11th 2018
If there’s a story that unites success in Silicon Valley and the new economy that’s given us iPhones and Uber, it’s that geek innovators are rewarded. Engineer the killer app and the cash will roll in. Big brains mean a big pay day. It may be a new economy, but this is a very old mistake. The idea that those at the top of a business are the ones who should be celebrated makes little sense to anyone who actually works in an organisation like Tesla. They might be the ones who make the headlines, but it’s the ordinary employees who do the work and produce the value.
Aug 15th 2018
The ability to reverse ageing is something many people would hope to see in their lifetime. This is still a long way from reality, but in our latest experiment, we have reversed the ageing of human cells, which could provide the basis for future anti-degeneration drugs.
Aug 14th 2018
We all like to think of ourselves as morally sound individuals. However in doing so we often assume that morality is static – that we are consistently moral to some extent over time. In reality, research suggests that most of us will behave in contradictory ways and act both morally and immorally from time to time. Interestingly, when we think about our past moral actions, we are likely to engage engage in compensatory behaviour and act immorally going forward.
Aug 8th 2018
This year marks the hundredth anniversary since the death of Gustav Klimt (1862-1918) and Egon Schiele (1890-1918), two of Austria’s greatest artists. That same year, 1918, also saw the end of the Austro-Hungarian Empire following its defeat in World War I – the end, that is, of an entire era, of a world. Fin de siècle Vienna was a place of extraordinary innovation – in music (with Arnold Schoenberg and the Second Viennese School), in literature (with Modernists such as Robert Musil and Herman Broch), in science (with Sigmund Freud and the development of psychoanalysis), and, of course, the visual arts, with the founding of the Vienna Secession in 1897, whose first president was Gustav Klimt. In Vienna, the rupture caused by the war was total: the city became the archetype of “a doomed society, in which brilliant achievements glowed in the gathering twilight.”
Jul 24th 2018
A decade ago, as the scale of the disaster in Iraq began to sink in, American historians often compared the United States to ancient Rome. Both seemed to suffer from an imperial disease whose symptoms began with overreach and ended in collapse. This is a useful way for Americans like me to consider our troubles abroad. But when it comes to our democracy’s problems at home, the closer parallel is with 18th century Britain, the “mother country” from which the United States broke away in 1776. Britons of that time enjoyed many liberties unknown to their favourite bogeymen, the French. These freedoms had many roots, including the Magna Carta of 1215, the Bill of Rights from 1689 and various parts of English common law. Most Britons saw their country as God’s favourite and thanked their “Constitution” — a general term for established forms of law and government — for their rising glory. Yet for all the liberties it tolerated, that Constitution’s real goal was to shield wealth and privilege from popular demands.
Jul 17th 2018
There are two ways of tackling chronic lifestyle diseases such as cancer, heart disease and diabetes: discover new drugs and treatments or persuade people to make positive lifestyle changes to avoid developing them in the first place. Health coaching is one of the most powerful ways of changing people’s mindsets for the long term. Practitioners are rapidly taking their place alongside executive coaches, life coaches and personal trainers as another means of making us better people through one-to-one improvement sessions.
Jul 16th 2018
Getting rid of loneliness is also about letting go of cynicism and mistrust of others. So next time you meet someone new, try to lose that protective shield and really allow them in, even though you don’t know what the outcome will be.
Jul 12th 2018
From the beginning Donald Trump’s administration has been marred by corruption and outright contempt for the rule of law – with the president’s firing of FBI Director James Comey “because of the whole Russia thing”, and persistent efforts to undermine Robert Mueller’s Russia probe; with his refusal to divest himself of private businesses, his attacks on judges who rule against him, and much else besides. Trump’s shameless claim to unbounded executive power manifested itself recently in repeated calls to deprive unauthorized immigrants of their due process rights. The conditions in migrant detention centers are horrifying and photos from one facility in McAllen, Texas showed children being held in cages. According to Senator Elizabeth Warren’s Facebook report, this border facility is an enormous warehouse “filled with cages. Cages for men. Cages for women. Cages for mamas with babies. Cages for girls. Cages for boys.”  Such an unconscionable state of affairs makes the current exhibition of Alberto Giacometti at the Guggenheim Museum in New York City all the more electrifying. The show features more than one hundred and seventy-five sculptures, paintings, and drawings, spanning more than forty years and across all the various media with which he worked.  
Jul 12th 2018
I sometimes meet with apologies from venues when a piano’s action may not be serviced to top form. I reply with a smile that such apologies are unnecessary, for in my youth I had to pull up as many keys as push down upon them when playing on battered uprights before elementary school children. In those days I played as often with my palms up as down, like a day at the gym dedicated to both push and pull. Once, however, just before a recital in a private South Carolina home, I encountered a woman whose main concern was – though my naked hands were plain before her – that I remove any rings I might be wearing before playing upon her piano’s vulnerable ivories.
Jun 12th 2018
Extract: “Nothing is beautiful except what is true,” Cézanne once said, “and only true things should be loved.” As the philosopher Jacques Derrida put it: “The truth in painting is signed Cézanne.” Perhaps it is this above all else that makes him the indispensible painter for our times, this era of so-called ‘post-truth.’ For Cézanne “painting was truth telling or it was nothing.” That is what it meant to paint from nature, to be primitive, to be free from all affectation, to be like those “first men who engraved their dreams of the hunt on the vaults of caves…” This is why we need to look and look again at Cézanne. And it is perhaps best that he has come to the National Gallery, to D.C., but a stone’s throw away from where truth is daily made a mockery of, and lies are proffered with breathtaking ease.
Jun 6th 2018
Extracts from the article: "Johnson and Johnson recently announced that it was halting a clinical trial for a new Alzheimer’s drug after safety issues emerged. This latest failure adds to the dozens of large, costly clinical trials that have shown no effect in treating this devastating disease. The growing list of failures should give us pause for thought – have we got the causes of Alzheimer’s all wrong?".............."Another option is to look at the risk factors for developing Alzheimer’s. One of these is type 2 diabetes." ............"Testing these [diabetes] drugs in animal models of another neurodegenerative disorder, Parkinson’s disease, also showed impressive effects, ............These new theories bring a fresh view on how these diseases develop and increase the likelihood of developing a drug treatment that makes a difference. To see any protective effect in the brain in a clinical trial is completely new, and it supports the new theory that Alzheimer’s and Parkinson’s disease are caused, at least in part, by a lack of growth factor activity in the brain. These new theories bring a fresh view on how these diseases develop and increase the likelihood of developing a drug treatment that makes a difference."
Jun 1st 2018
Extract from the article: "The most common defense of truth is the pragmatic one – namely, that truth works; that true beliefs are more likely to get the job done than those that are not true. The pragmatic account of the value of truth is not wrong, but at the same time it is not enough. Truth is not valuable for solely instrumental or extrinsic reasons. Truth has intrinsic value as well. When we reduce the value of truth to instrumentality, it is a very short step to saying that we just want beliefs that work for us, regardless of whether they are true or not."
May 14th 2018
During the first century of modern art, Paris was a magnet for ambitious artists from all over Europe. Remarkably, the current exhibition at Paris’ Petit Palais tells us that “Between 1789 and 1914, over a thousand Dutch artists traveled to France.” Prominent among these were Ary Scheffer, Johan Jongkind, Jacob Maris, Kees van Dongen. But of course most prominent were Vincent van Gogh and Piet Mondrian.