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Dementia

A New Study Links Oral Health and Brain Health

Brain changes years in advance of dementia reflect poor oral health.

Key points

  • Poor dental health can result in dementia, Alzheimer's, and stroke.
  • Gum disease and poor oral health can damage the white matter in the brain.
  • Poor oral health is a common public health problem, affecting nearly 50% of people over age 30.
  • Committing resources to improving oral health will do more than improve people’s smiles.

Mental health professionals are rarely given an easy and straightforward solution to anything having to do with the mind and the brain. However, a group of researchers from Yale has released a study about gum disease and cognitive decline that does just that.

Studies have shown that poor oral health such as periodontitis and tooth loss are risk factors for cognitive decline, dementia, and stroke, but until now, those studies have only been observational. It is also known that improving oral health can have a favorable effect on Alzheimer’s-related brain atrophy, but the effect has been shown to occur after symptoms have begun and a diagnosis of Alzheimer’s has been clearly established.

Until now, no studies have shown that poor oral health actually causes brain changes that occur years before the onset of Alzheimer’s disease and stroke.

However, a recent study, by Rivier et al [1], found that poor oral health causes brain changes that are associated with the onset of dementia and stroke years before cognitive decline is observable. From the study: “We found that individuals with poor oral health had higher WMH (white matter hyperintensities) volume and worse white matter architecture profiles, even after adjusting for confounding factors.”

Depositphotos
Source: Depositphotos

What are “white matter hyperintensities”?

The brain consists of white matter and gray matter. Gray matter is made up of nerve cell bodies, often referred to as the processing areas of the brain and spinal column. The nerve fibers that connect areas of gray matter to each other and to the spinal cord are known as white matter. One way of thinking of this is that the white matter makes up the cables or networking system that connects the different gray-area processing centers.

White matter is white because the nerve fibers are covered by a fatty myelin sheath. Myelin insulates the fibers and helps them to speed signals along the nerve circuits. White matter hyperintensities represent small lesions that result from damage to the myelin and to the nerve fibers in the white matter. This type of damage, which can show up on MRIs, causes a slowing of the signals transmitted in the brain, which can lead to cognitive decline.

The study by Rivier et al shows that gum disease and poor oral health can damage the white matter in the brain, which can contribute to cognitive decline and stroke.

Unfortunately, poor oral health is a common public health problem. The New York Times recently reported that nearly half of Americans over the age of 30 show signs of gum disease. And once gum disease begins, it is not something that can be cured by better brushing and flossing. It requires intervention by a dentist.

Yet few people have dental insurance, and preventative dental care is often a luxury that many cannot afford. When I was in my twenties and thirties, I couldn’t afford routine dental care. Fortunately, there were dental schools in the cities where I was living, and I was able to get dental care at a fraction of the cost. So if your finances are tight, find out whether there’s a dental school in the area that provides care on a sliding fee scale.

What’s particularly important about the new study is that it is the first to show that committing resources to improving oral health will do more than improve people’s smiles. Providing assistance could have long-term cognitive health benefits that will pay for dental care many times over.

I’m not sure whether this means that, as psychotherapists, we should be giving our patients toothbrushes and dental floss. But in our writing and presentations, we should definitely mention the importance of oral health as a way of helping to prevent cognitive decline. I certainly will be doing that in my podcast for men, which is something I would never have thought to do before reading this study.

References

[1] Poor Oral Health Is Associated with Worse Brain Imaging Profiles Cyprien A. Rivier, Daniela Renedo, Adam de Havenon, Thomas M. Gill, SamPayabvash, Kevin N. Sheth, Guido J. Falcone medRxiv 2023.03.18.23287435; doi:https://doi.org/10.1101/2023.03.18.23287435. (This is a preprint, but looks very solid based on my reading of the methodology and number crunching.)

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