Bonus Track

How Your Eyes, Ears and Mouth Connect to Your Brain Health

Photo by Jonathan Cooper on Unsplash

I am prepping for my second brain resilience workshop, spearheaded by friend and health coach Sophie Mayo. The session is aimed at arming people with doable lifestyle changes and habits to help protect against Alzheimer’s and dementia.

The suggestions are based on the Lancet Report on dementia prevention intervention and care that identifies 14 modifiable risk factors that, when addressed, can together potentially prevent or delay more than 45 percent of dementias. This time, we’re adding a Bonus Track to the presentation by talking about the role of vision, hearing and oral health in maintaining brain health.

Hearing loss was added to the list of risk factors in 2020, and vision loss was added in 2024. Together they account for 9 percent potential risk reduction. Oral health, while not officially recognized in the Lancet report as a risk factor, has long been associated with overall health, including brain health. To me, that connection was less intuitive, until I went down many rabbit holes in the Internet, including some fascinating podcasts and (of course) purchases. I’ll share those later because I would not want anyone to miss out on that fun! Long story short, I now totally get the oral health connection and am a floss-waving believer.

LET’S START WITH THE EARS

Hearing loss is considered the largest modifiable risk factor for dementia in mid-life, with studies showing that untreated hearing loss, depending on the severity, can increase dementia risk by 200–500%. Specifically, a Johns Hopkins study that tracked 639 adults for nearly 12 years broke it down like this: mild hearing loss doubled dementia risk, moderate loss tripled risk, and a severe hearing impairment left people five times more likely to develop dementia.

This connection has multiple drivers. The most obvious is that poor hearing leads people to withdraw socially, which leads to loneliness and depression (another risk factor). Withdrawal prevents people from reaping the benefits of social interaction and also kicks off a cycle of reduced brain stimulation.

Furthermore, impaired hearing leads to increased “brain strain” or cognitive load. More cognitive resources spent decoding sounds and giving them meaning, means less brain power is available for memory and thinking.

As if those aren’t penalty enough, impaired hearing leads to structural brain changes, including accelerated atrophy in the area of the brain that processes sound; and less input means less brain stimulation which in turn leads to weakened neural pathways. Fun stuff. The good news is that getting hearing aids AND USING THEM can significantly reduce the risk of getting dementia. Some studies show a 32% lower prevalence of dementia among hearing aid users.

AND NOW TO THE EYES

Nearly 1 in 5 dementia cases are linked to vision impairment. Vision loss can be both a symptom of Alzheimer’s disease, accelerating cognitive decline, and a potential contributor to it. As a symptom, Alzheimer’s often damages the brain’s visual processing centers, causing vision problems even if the eyes are healthy. The same amyloid-beta and tau that damage the brain in Alzheimer’s can also affect the retina and visual pathways. This can lead to reduced contrast sensitivity, poor depth perception, reduced visual field and a severe visual dysfunction called Posterior Cortical Atrophy (PCA).

For this conversation, we’re more concerned about vision loss as a risk factor (contributor) to Alzheimer’s, because that’s where we can do something about it. As with hearing, vision resides in a use it or lose it zone, and impacts the brain in multiple ways. Less sensory data coming in means less brain stimulation which makes the brain more vulnerable to degenerative disease. It also leads to withdrawal from social activities and physical exercise. Isolation and inactivity are two significant risk factors for Alzheimer’s and dementia. As with poor hearing, when your brain gets blurry or incomplete visual images it takes more cognitive power to interpret them, leaving less power for all the other stuff your brain could otherwise be tackling. It also exacerbates confusion, and increases the risk of falls, hence the withdrawal from physical exercise.

The good news, again, is that most vision problems (some sources say more than 90%) are preventable, treatable, or curable. That includes cataracts, glaucoma, and refractive errors (near- and far-sightedness, astigmatism, presbyopia) that can often be avoided or corrected through early detection, regular eye exams and proper eye protection.

AND FINALLY TO THE MOUTH

Here’s the newcomer on the block, despite a long history of an associative relationship between dementia and poor oral health. As with vision, oral health appears to be bidirectional—both a cause (contributor) and effect (symptom) of Alzheimer’s and dementia.

Emerging research indicates a strong, plausible link between poor oral health—specifically chronic gum disease—and an increased risk of Alzheimer’s disease. The main perps are the bacteria Porphyromonas gingivalis (that’s P gingivalis between friends), that cause gum disease and thrive in an environment of poor oral hygiene. They can enter the bloodstream through inflamed gums, and cross the blood brain barrier. There, they produce toxic enzymes that cause neuroinflammation and the accumulation of amyloid-beta plaque, which is basically Alzheimer’s business card.

But wait there’s more! Oral microbiome dysbiosis—where harmful bacteria dominate beneficial ones—is the canary in the coal mine for all manner of health issues. The same environment that let oral bacteria thrive is also linked to the systemic inflammation that leads to cardiovascular disease, stroke, type 2 diabetes, obesity etc.

MAJOR IN THE MAJORS

So, what can you do? As with hearing and vision, there are some pretty basic ways to protect yourself. There’s this thing called a toothbrush; and another thing called floss. Daily use of both is non-negotiable. Consistency is also key with regular cleanings and check-ups to stay on top of gum disease and dental issues. If, like some of us, you want to go down some rabbit holes on the topic, you can go the extra mile by daily tongue scraping and using plastic-free silk floss. I am now the proud owner of both. If all that is overwhelming, do as Dr Mark Burhenne of Askthedentist.com advises: “Major in the majors.” That means brushing twice a day, flossing once a day and getting regular cleanings and check-ups.

I realize that felt a little bit like school today; but it did help me study up for my workshop, so thank you for playing and I hope you got something out of it!

If you’re local and want to check out our Brain Health session come on out to Community Care of Lyme tomorrow (Thursday March 19) at 4:30pm.