Findings from a study published in the journal Neurology suggest that poor dental health is linked to hippocampal atrophy, or shrinkage of the hippocampus, which is a marker for Alzheimer’s disease.
Brain shrinkage linked to poor oral health
Study author Satoshi Yamaguchi, an associate professor at Tohoku University Graduate School of Dentistry in Sendai, Japan, explained that retaining more healthy teeth without periodontal disease may help support brain health.
Because periodontal disease is also associated with systemic inflammation and bacteria in the bloodstream, which may cause chronic disease, keeping your teeth, mouth and gums healthy can help boost your overall health.
Someone with poor oral hygiene can develop gingivitis, which is an inflammatory disease caused by an accumulation of plaque (bacteria) on your teeth that often results in bleeding gums.
When left untreated, gingivitis can cause periodontitis, which is a more serious infection that can lead to teeth loss.
Periodontitis is a type of gum disease that has been considered a potential risk factor for Alzheimer’s since 2015, when scientists from the University of Bristol reported that "periodontal pathogens are possible contributors to neural inflammation and SLOAD [sporadic late onset Alzheimer’s disease]."
In the Neurology study, researchers worked with 172 volunteers aged 55 years and over who had no cognitive decline at the start of the study.
The volunteers underwent dental exams and took memory tests. The research team also conducted brain scans to measure their hippocampus volume at the start of the study and four years later.
Results showed that both gum disease and number of teeth were linked to brain changes.
The volunteers with mild gum disease and fewer teeth had a faster rate of shrinkage in the left hippocampus. Among this group, having one less tooth increased brain shrinkage at a rate equivalent to at least a year of brain aging.
Among the volunteers with severe gum disease, having more teeth was linked to a faster rate of brain shrinkage, with one more tooth being equivalent to 1.3 years of brain aging.
In a news release, Yamaguchi explained that tooth loss and gum disease, which is "inflammation of the tissue around the teeth that can cause shrinkage of the gums and loosening of the teeth," are very common and analyzing any possible links with dementia is crucial.
The Neurology study revealed that these conditions may have a role in the health of the brain region that controls thinking and memory, giving people another reason to maintain proper oral health.
Bacteria linked to gum disease can travel to the brain
In 2019, researchers from the University of Louisville found Porphyromonas gingivalis, a pathogen linked to chronic periodontitis, in the brains of patients with Alzheimer’s. Gingipains, the toxic proteases from P. gingivalis, were also found in the brains of patients with the brain disorder.
The researchers reported that gingipains are linked to two protein markers of Alzheimer's: Tau and ubiquitin. (Related: Maintaining good oral health key to preventing Alzheimer’s disease, reports study.)
In mice subjects, oral infection with P. gingivalis resulted in brain colonization of the pathogen and increased production of amyloid beta 1-42, which is found in amyloid plaques.
Findings from both in vivo and in vitro studies revealed that gingipains are neurotoxic and damaging to tau, which is essential for normal neuronal function.
Gingipain antigens were also detected in the brains of people with Alzheimer’s as well as in those with Alzheimer’s pathology who had not yet been diagnosed.
Based on these, the researchers believe that brain infection with P. gingivalis is not a result of poor dental care following the onset of dementia or a consequence of late-stage disease. Rather, it is an early event that can clarify the pathology observed in middle-aged people before cognitive decline.
Data also suggests that bacteria may access the brain from an infected oral cavity via infection of endothelial cells protecting the blood-brain barrier or infection of monocytes (white blood cells) that reach the brain.
After entering the brain, P. gingivalis may gradually spread over many years from neuron to neuron along anatomically connected pathways, like what has been demonstrated for vascular cell-to-cell transmission of P. gingivalis, explained the researchers.
Periodontal disease linked to Alzheimer’s disease
People diagnosed with Alzheimer’s usually have poor oral health, which has commonly been associated with declining self-care or neglect of oral health by caregivers.
Older studies also suggest that periodontal disease may be a contributing factor in the development of Alzheimer's.
One systematic review and meta-analysis that included 13 studies revealed that the risk of Alzheimer’s and mild cognitive impairment in those with severe periodontal disease was much higher compared to people without periodontal disease.
Gum disease is a "silent condition"
Data shows that among adults aged 30 or over, 46 percent have signs of gum disease, while nine percent of adults already have severe gum disease.
Unfortunately, many people are not aware they have it because gum disease is often a "silent" condition, meaning it often doesn't show signs and symptoms until it reaches more advanced stages.
In the initial stage of gingivitis, you may notice that your gums bleed when you are brushing your teeth, flossing, or eating hard food. Your gums may also appear red or swollen.
As the disease progresses, you will notice that your gums may pull away from your teeth, making your teeth appear longer. In some cases, your teeth may also become loose. You may also notice sores in your mouth, bad breath and pus between your gums and teeth.
Aside from cognitive decline, periodontitis has been linked to systemic diseases, such as:
- Adverse pregnancy outcomes
- Cancer
- Diabetes
- Heart disease
- Nervous system diseases
- Respiratory disease
Protecting oral health early on is crucial
Because deposits of amyloid beta in the brain may start one to two decades before cognitive decline and diagnosis of Alzheimer’s, and periodontal disease may also be persistent for at least 10 years to initiate Alzheimer’s, maintaining good oral health early on can help prevent the disease.
This is crucial not just for older adults, but also for middle-aged and younger adults, who can support their brain health by maintaining proper oral health.
Even in young, otherwise healthy, adults, episodic memory and learning rate is improved among people with good oral health compared to those with aggressive periodontal disease, which implies that damage to brain health may start early on.
Maintain proper oral hygiene with regular brushing, flossing and tongue scraping. You should also use fluoride-free toothpaste.
Never go to bed at night without brushing your teeth and limit your intake of sugary and acidic foods to keep your teeth and gums healthy.
Watch the video below for tips on how natural toothsalt with neem can help maintain oral health.
This video is from the Health Ranger Store channel on Brighteon.com.
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