Are the bacteria in your mouth guilty of causing dementia?


Dementia is a heart-breaking, slowly progressive disease that results in a gradual loss of memory and cognitive function. It’s life-crushing for both the individual who has it and also their loved ones.

Alzheimer’s is by far the most common form of dementia and accounts for 60-70% of all cases. For years the cause has been attributed to the accumulation of proteins (amyloid and tau) in the brain, and so most research has been centred on this theory. Unfortunately, there hasn’t been any breakthrough.   

Recent research

Recently, however, research has implicated bacteria customarily associated with gum disease as a possible cause of Alzheimer’s.  In a nutshell, researchers may have discovered that the proteins previously accused of causing Alzheimer’s may have been a red herring as they may be a defence mechanism against invading bacteria. Experiments on mice have found that the bacteria Porphyromonas gingivalis ( considered one of the primary bacteria responsible for gum disease) can invade brain tissue, cause brain inflammation, bring about amyloid protein formation, and lead to neural damage similar to what has been observed in the brains of deceased sufferers of Alzheimer’s.  Furthermore, Porphyromonas gingivalis releases toxic enzymes called gingipains. These toxic enzymes which help the bacteria feed on human brain tissue have been found in over 96% of brain samples taken from sufferers of Alzheimer’s.

Finally, the DNA of Porphyromonas gingivalis has also been detected in living patients’ spinal fluid. All of these findings suggest that oral bacteria normally associated with gum disease may play a significant role in the aetiology of Alzheimer’s.  

But how do the bacteria get to the brain?

With gum disease, the area of the gum next to the tooth root develops lots of small ulcers. These ulcers can be looked upon as open wounds which provide a direct gateway for the oral bacteria to enter the bloodstream and then get transported to distant organs.

Does having gum disease mean I will get dementia?

Unfortunately, about 45% of the UK population have gum disease which results in bone loss, loose or wobbly teeth or teeth that start to drift.

If the findings hold up, do they mean that everyone with gum disease will develop Alzheimer’s? Not necessarily. Disease is very rarely caused by a single entity, and there are probably multiple-factors involved with genetic susceptibly and lifestyle no doubt playing a part.

What can you do to minimise your risk?

If you want to stay on the safe side and potentially reduce your risk:

1.    Visit your dentist to get your gums checked. We can detect the earliest signs of gum disease and the earlier, the better.

2.    See your hygienist who will remove tartar deposits (which can exacerbate gum disease)  and show you how best to keep your mouth clean and healthy and minimise the harmful bacteria inside your mouth.

3.    Use an effective homecare programme.

4.    Stop smoking as smoking makes your gum disease worse and harder to treat.

Davinder Raju.

Davinder Raju