16 Common Health Conditions Linked to 18.8 Million Dementia Cases
Have you ever considered that your routine dental cleaning might matter just as much for your brain as it does for your teeth? Or that getting your hearing checked could be a form of dementia prevention?
I know it sounds strange. But mounting evidence suggests that conditions affecting our gums, liver, hearing, and other parts of our body may be much more intimately connected to our cognitive health than we ever realized.
We already know that lifestyle factors like exercise, diet, and sleep play crucial roles in cognitive health. And researchers have long understood that conditions like high blood pressure and diabetes can affect dementia risk.
But what we haven't had until now is a comprehensive picture of just how much of the global dementia burden might be connected to diseases affecting other parts of our body—from our gums to our liver to our joints.
A massive new analysis1 decided to quantify exactly that. Researchers examined data from over 200 studies to understand which health conditions outside the brain are most strongly associated with dementia, and more importantly, what percentage of dementia cases worldwide might be linked to these seemingly unrelated diseases.
Connecting the dots between body & brain
Researchers at Sun Yat-sen University conducted a systematic review and meta-analysis examining 26 different peripheral diseases, conditions that affect parts of the body outside the brain, and their relationship to dementia risk.
They analyzed data from the Global Burden of Disease Study and the UK Biobank, looking at trends across different ages, sexes, and geographic regions from 1990 to 2021.
What made this study particularly powerful was its approach. Rather than just identifying whether these conditions were associated with dementia, the researchers calculated what's called the "population attributable fraction," essentially, the proportion of dementia cases that could statistically be linked to each condition. This gives us a much clearer picture of which health issues might matter most for brain health at a population level.
One-third of dementia cases linked to peripheral diseases
The 16 peripheral diseases identified in the study were collectively associated with approximately 33% of dementia cases globally. That's roughly 18.8 million people whose cognitive decline may be connected to health conditions outside their brain.
The top contributors were conditions that many of us deal with or know someone who does. Periodontal disease (yes, gum disease) was linked to about 6% of the dementia burden. Chronic liver diseases accounted for roughly 5.5%. Hearing loss contributed nearly 5%, while vision loss was associated with about 4%, and type 2 diabetes with roughly 4%.
The full list of associated conditions included chronic kidney disease, osteoarthritis, stroke, ischemic heart disease, COPD, asthma, atrial fibrillation, eczema, rheumatoid arthritis, multiple sclerosis, and inflammatory bowel disease.
What’s striking is how common and often manageable many of these conditions are.
What this means for your health
While this study shows associations rather than direct causation, the findings suggest that managing these peripheral conditions could be an important part of protecting cognitive health. Here's what you can do:
- Take oral health seriously. Treating gum disease and maintaining good dental hygiene may have benefits beyond your smile.
- Protect hearing and vision. Early screening and correction can reduce cognitive strain and social withdrawal.
- Manage metabolic health. Blood sugar control and insulin sensitivity matter for both brain and body.
- Address chronic inflammation. Managing autoimmune, respiratory, and inflammatory conditions may help reduce long-term neurological stress.
- Prioritize cardiovascular health. What supports your health & healthy blood flow also supports brain aging.
The takeaway
Our bodies are deeply interconnected systems. The health of your gums, liver, kidneys, and sensory organs doesn't exist in isolation from your brain health.
The hopeful message here is that we may have more opportunities for prevention than previously understood. While we can't control every risk factor for dementia, many of these peripheral conditions are detectable, treatable, and in some cases preventable.
That regular checkup you've been postponing? It might be protecting more than you realize.
