Why Brushing Your Teeth Regularly May Help Prevent Alzheimer's and Certain Other Brain Diseases

Who knew your toothbrush could be a secret weapon in maintaining not only a bright smile but also a sharp mind? A recent study published in the peer-reviewed science journal Neurology suggests that gum disease can be linked to specific brain issues.

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Before you jump to conclusions, let's make it clear - the study does not imply that losing teeth or having gum disease can cause Alzheimer's disease. But, it does hint at a connection between dental issues and negative changes in the brain.

According to Dr Satoshi Yamaguchi, from the Division of Aging and Geriatric Dentistry at Tohoku University in Japan, tooth loss and gum disease are widespread issues; therefore, looking into their possible connection with memory/brain problems could be very relevant. His team found that dental problems might affect the health of a specific part of your brain, which plays a role in memory and Alzheimer's disease, known as the hippocampus.

Gum disease has been linked with Alzheimer’s disease before

Previous studies have established a connection between gingivitis, a form of gum disease, and Alzheimer's disease.

The destructive journey starts when bacteria that instigate gum disease migrate from the mouth to the brain. There, these bacteria excrete enzymes known as gingipains, which have the potential to demolish nerve cells. This can culminate in memory loss and, in time, Alzheimer's. The toxic materials generated by gingipains are intrinsically connected to the concentrations of proteins named tau and ubiquitin, both of which have been implicated in the progression of Alzheimer's disease.Furthermore, senior citizens exhibiting indications of gum disease and oral infections were found to be more susceptible to developing Alzheimer's within the research duration.

The connection between gum disease and Alzheimer's remains somewhat elusive, yet it's conjectured that the body's inflammatory reaction to gum disease may contribute to the cognitive decline associated with Alzheimer's. Infections may not be the primary origin of Alzheimer's disease, but they can serve as contributing factors. By brushing teeth twice daily, flossing at least once a day, and scheduling regular dental examinations, one can help ward off gingivitis and decrease the risk of Alzheimer's disease.

Further reading: You’re probably brushing your teeth wrong – here are four tips for better dental health (Universal-Sci)

The study

The new study by Dr Satoshi Yamaguchi involved 172 people with an average age of 67 who did not have memory problems at the beginning of the research period. 

Participants had dental exams and took memory tests at the beginning of the study. They also had brain scans to measure the volume of the hippocampus at the beginning of the study and again four years later.

The researchers used a test to check for gum disease, measuring the 'pockets' between teeth and gums. A reading of one to three millimetres is healthy. If you have three or four millimetres in several places, that means mild gum disease. Five or six millimetres means severe gum disease, which could make your teeth loose or even fall out.

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Results

The team uncovered a link between the number of teeth and the degree of gum disease and changes in the left hippocampus of the brain. Interestingly, the correlation was different for those with mild and severe gum disease.

For people with mild gum disease having fewer teeth was associated with a faster rate of brain shrinkage in the left hippocampus. However, for people with severe gum disease having more teeth was associated with a faster rate of brain shrinkage in the same area of the brain. Meaning that, in some cases, it may be a smart move to take out teeth that are severely affected by gum disease and replace them with false teeth.

After accounting for age, the researchers discovered that for those with mild gum disease, the accelerated rate of brain shrinkage due to one less tooth was akin to nearly a year of brain ageing. Contrarily, for individuals with severe gum disease, the increased rate of brain shrinkage due to one additional tooth equated to 1.3 years of brain ageing.

Related article: Alzheimer's is linked to gum disease – but bad oral health is not the only culprit

The takeaway

Dr Yamaguchi explains that these results highlight the importance of taking care of your teeth, not just keeping them. Their findings suggest that having teeth with severe gum disease may be linked to brain shrinkage. Yamaguchi stresses that regular dentist visits are crucial to controlling gum disease.

While these findings are significant, Dr Yamaguchi remarked that future research should involve larger groups of people. He also pointed out that since the study was conducted in a specific region in Japan, the findings might not be applicable worldwide.

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