Can going to the dentist give you Alzheimer’s?
That’s what a shock study claimed. Yet avoiding regular check-ups puts you at even greater risk
VISITING the dentist is already frightening enough for many of us, but last week’s shock headlines warning that alzheimer’s disease may potentially be transmitted via dental surgery makes it even more daunting.
New research by Professor John collinge, a neurologist at University college London, suggested that amyloid beta, a protein that forms one of the critical components of the l ethal brain disease, may possibly be transmitted by contaminated instruments.
This protein builds up into small clumps which scientists believe block signals between brain cells, causing alzheimer’s.
amyloid beta ‘sticks avidly’ to metal and it is not currently known if it can be killed off by conventional sterilisation, said Professor collinge, who added: ‘One would have to consider whether certain types of dental treatment are relevant.’
he later said more research was needed before drawing any conclusions about any potential risks.
But this is not the first time that dental and other forms of surgery have been linked to dementia. a southampton University study, published in the journal Neurology in 2011, suggested it could speed up the progress of alzheimer’s in people who already had the disease in its early stages.
clive holmes, a professor of biological psychiatry at southampton, said the early stages of the disease may make the brain more sensitive to the chemicals the body produces to promote recovery, triggering Researchers severe alzheimer’s. an infection or physical injury could have the same effect.
monitored 300 British patients with mild alzheimer’s for six months. Those who had undergone dental or medical surgery that triggered an i ncrease i n the production of white blood cells (which help the body recuperate) experienced a tenfold increase in the rate of cognitive decline.
surgery also triggered a cascade of healing inflammatory proteins that communicate with the nerve cells in the brain, causing lethargy, sleepiness and lack of focus.
This normally helps the body recover by enforcing rest. But with early-stage alzheimer’s it seems the proteins have a harmful effect. Professor holmes told Good health at the time this could turn ‘someone with mild alzheimer’s . . . into a person who requires roundthe-clock care’.
But don’t let all this make you ignore the dentist’s next reminder. Because more and more research indicates that this would increase your risk — because long-term, low-grade infections such as gum disease cause inflammation, and it’s this that may be the key.
Inflammation is a healthy body’s response to infection. But persistent infection can push our immune system into damaging overdrive, setting off potentially harmful chain reactions.
a common cause of chronic inflammation i s gum disease, often starting around the age of 30. The Nhs says more than half of UK adults have some degree of gum disease in two main forms.
Gingivitis is when the gums around the teeth redden, swell and often bleed when brushed.
Long- standing gingivitis can turn into periodontal disease, which can then destroy the bone anchoring the teeth in the jaw. Up to one in six UK adults is thought to have severe periodontitis, also a possible trigger for alzheimer’s according to specialist Dr sim singhrao of the University of central Lancashire’s Oral and Dental sciences research Group.
her study, published this year in the journal Neurobiology of aging, found that in healthy women aged 60, the brains of those with the worst periodontal disease had more of the amyloid beta clumps.
and in a post-mortem study of alzheimer’s patients’ brains, she found evidence of a bacterium, Porphyromonas gingivalis, linked to periodontal disease. It was not found in brains unaffected by alzheimer’s. animal studies confirmed the bacterium could spread from mouth to brain.
‘Bacteria that cause periodontal disease are such clever organ- isms,’ Dr singhrao explained. ‘ They can trick the i mmune system into letting them survive in our bodies for decades. If you contract these virulent bacteria in your 30s and they aren’t controlled you are in danger of getting a She delayed response decades later.’
added: ‘This can be in the form of alzheimer’s disease, which can occur at about the age of 80.’ scientists don’t yet know why gingivitis turns into periodontal disease for some people and not for others. ‘Poor dental hygiene is a factor,’ says Dr singhrao. ‘Once you have chronic periodontal disease, you can’t get rid of it entirely, but we can control it.’
she fears Professor collinge’s findings have caused a ‘public scare’ that may put people off visiting dentists, the very people who can control gum disease.
‘ This c ould help prevent alzheimer’s,’ she said.
The southampton team is now studying how inflammation speeds up alzheimer’s. hugh Perry, a professor of experimental neuropathology, believes the early ‘protein clumps’ stage prompts the brain’s immune cells, microglia, to multiply to dispose of them.
But this makes the microglia extra- sensitive, and signals sent as a result of chronic inflammation such as periodontal disease or surgery can push them into a hyperactive state in which they attack healthy neurons, boosting the progress of alzheimer’s.
Professor Perry’s team recently ran a pioneering trial on 40 people to see if etanercept, a drug that dampens inflammation and is already prescribed for rheumatoid arthritis, helps slow down the
FOR progress of alzheimer’s. a six-month study published in Neurology in May, etanercept was given to 20 people with mild alzheimer’s, who were compared to similar patients who took a placebo.
‘What we clearly saw is that the arrow is pointing in the right direction,’ said Professor Perry. ‘ The people on the placebo drug continued to decline, but the progression of the disease was delayed in those on etanercept. We are now doing further studies on this.’
Dr emma O’Brien, of alzheimer’s research UK, says there are other links between periodontal disease and dementia.
‘There is some evidence that the inflammation periodontitis causes may interact with the brain,’ she explains. ‘It may cause the protective barrier around it to become more leaky, allowing more inflammation into the brain, which may then damage cognitive function.’
Dr O’Brien adds: ‘Periodontitis is also associated with type 2 diabetes — also associated with a greater risk of alzheimer’s.’
The sensible response, according to Professor Perry, is to maintain healthy habits that keep our bodies and brains in good order.
he adds: ‘ We already know the risk factors for alzheimer’s are all associated with chronic low-grade bodily inflammation, such as periodontal disease, as well as smoking, obesity and type 2 diabetes.
‘These can all be addressed by lifestyle c hanges, s uch as l osing weight and stopping smoking — and visiting your dentist regularly.’