The Link Between Type 2 Diabetes and Dementia — And Why Reversing Diabetes Matters More Than You’ve Been Told

By: Marcy Schoenborn

Type 2 diabetes is often talked about as a blood sugar problem.

It’s not.

It’s a metabolic disease that affects every system in the body — including the brain. And the longer it goes unaddressed, the greater the long-term consequences.

One of the most concerning (and least discussed) consequences is this:

People with type 2 diabetes have a significantly higher risk of developing dementia, including Alzheimer’s disease and vascular dementia.

The good news?
This risk is not inevitable — especially when diabetes is prevented, improved, or put into remission through lifestyle-based approaches.

How Type 2 Diabetes Increases Dementia Risk

Research consistently shows that people with type 2 diabetes have about a 60% higher risk of developing dementia compared to those without diabetes. The longer diabetes is present — and the earlier it begins — the higher that risk becomes.

Why does this happen?

1. Insulin Resistance Affects the Brain

Insulin isn’t just about blood sugar — it’s also involved in brain signaling, learning, and memory. When the body becomes insulin resistant, the brain can too.

This impaired insulin signaling in the brain interferes with:

• Memory formation

• Neuron survival

• Normal glucose use by brain cells

Because of this, Alzheimer’s disease is sometimes referred to as “type 3 diabetes.”

2. Chronic High Blood Sugar Damages Blood Vessels

Persistently elevated glucose damages both small and large blood vessels. In the brain, this means:

• Reduced blood flow

• Increased risk of strokes and micro-infarcts

• Higher likelihood of vascular dementia

Healthy cognition depends on healthy circulation — and diabetes compromises that.

3. Inflammation and Oxidative Stress Accelerate Brain Aging

Type 2 diabetes creates a state of chronic inflammation and oxidative stress. These processes:

• Damage neurons

• Promote abnormal protein accumulation (such as beta-amyloid)

• Speed up brain aging

Even prediabetes has been associated with structural brain changes and cognitive decline.

The Most Important Part: This Risk Can Be Reduced

Here’s where the conversation changes.

Diabetes does not automatically mean dementia.
What matters most is whether metabolic dysfunction continues — or whether it’s corrected.

Lifestyle-based interventions that restore insulin sensitivity and normalize blood sugar have been shown to:

• Reduce vascular damage

• Improve metabolic signaling in the brain

• Slow cognitive aging

In many cases, early type 2 diabetes can enter remission — meaning blood sugar levels return to the non-diabetic range without medications.

What Diabetes “Reversal” or Remission Really Means

Reversal doesn’t mean the body forgets it was ever vulnerable.

It means:

• Blood glucose is controlled naturally

• Insulin sensitivity is restored

• The metabolic environment damaging tissues and organs is removed

This dramatically lowers the downstream risks associated with diabetes — including those affecting the brain.

I know this isn’t theoretical — because I’ve lived it.

My own type 2 diabetes has been reversed for over 9 years through lifestyle, not medications.
That matters, because duration counts. Long-term normalization of blood sugar and insulin reduces cumulative damage over time.

This isn’t about short-term fixes.
It’s about changing the trajectory of health and aging.

What Actually Helps Reverse or Prevent Type 2 Diabetes

The approaches with the strongest evidence all focus on addressing root causes — not just managing numbers.

Nutrition That Supports Metabolic Health

Whole, nutrient-dense foods — particularly plant-forward diets rich in fiber, phytonutrients, and adequate protein — improve insulin sensitivity and stabilize blood sugar.

This is not about starvation or extreme restriction.
It’s about cellular nourishment.

Movement That Builds Insulin Sensitivity

Regular physical activity improves glucose uptake by muscles, reduces insulin resistance, and supports vascular health — all of which protect the brain.

Reducing Excess Body Fat (Especially Visceral Fat)

Even modest weight loss (5–10%) can significantly improve metabolic markers and support remission in early diabetes.

Supporting Sleep, Stress, and Recovery

Poor sleep and chronic stress elevate cortisol, worsen insulin resistance, and increase inflammation — undermining both metabolic and cognitive health.

Why This Matters for Brain Health

When diabetes is reversed or prevented:

• The brain is no longer exposed to glucose toxicity

• Blood vessels remain healthier

• Inflammation decreases

• Cognitive decline risk is reduced

In simple terms:

You’re not just protecting blood sugar — you’re protecting your brain.

How I Help

I work with people who are tired of chasing symptoms and want to address the why behind metabolic dysfunction.

My programs focus on:

• Restoring insulin sensitivity

• Nourishing the body at a cellular level

• Creating sustainable lifestyle change (not short-term fixes)

• Supporting long-term metabolic and cognitive health

This isn’t about perfection, extremes, or willpower.

It’s about understanding how the body works — and giving it what it needs to heal.

If you’re concerned about diabetes, prediabetes, or long-term brain health, know this:

There is more you can do than you’ve been told — and it works when done correctly.

Core Diabetes–Dementia Link

1. Biessels, G. J., et al. (2006).
   Risk of dementia in diabetes mellitus: a systematic review.
   The Lancet Neurology, 5(1), 64–74.

   Found ~50–60% increased dementia risk in people with type 2 diabetes.

2. Cheng, G., et al. (2012).
   Type 2 diabetes as a risk factor for dementia: a systematic review and meta-analysis.
   Diabetes Care, 35(12), 2668–2676.

   Confirmed increased risk for both Alzheimer’s disease and vascular dementia.

3. Arnold, S. E., et al. (2018).
   Brain insulin resistance in type 2 diabetes and Alzheimer disease.
   Nature Reviews Neurology, 14(3), 168–181.

   Describes insulin resistance in the brain and the “type 3 diabetes” concept.

Mechanisms: Insulin Resistance, Vascular Damage, Inflammation

4. Craft, S. (2009).
   The role of metabolic disorders in Alzheimer disease.
   Archives of Neurology, 66(3), 300–305.

5. de la Monte, S. M., & Wands, J. R. (2008).
   Alzheimer’s disease is type 3 diabetes.
   Journal of Diabetes Science and Technology, 2(6), 1101–1113.

6. Kodl, C. T., & Seaquist, E. R. (2008).
   Cognitive dysfunction and diabetes mellitus.
   Endocrine Reviews, 29(4), 494–511.

7. Strachan, M. W. J., et al. (2011).
   Type 2 diabetes and cognitive decline.
   Diabetologia, 54(2), 300–309.

Prediabetes, Brain Aging & Early Intervention

8. Rawlings, A. M., et al. (2018).
   Diabetes in midlife and cognitive change over 20 years.
   Annals of Internal Medicine, 169(9), 599–607.

9. Geijselaers, S. L. C., et al. (2015).
   Glucose regulation, cognition, and brain MRI in type 2 diabetes.
   Diabetes Care, 38(5), 827–835.

Diabetes Reversal / Remission Through Lifestyle

10. Lean, M. E. J., et al. (2018).
    Primary care–led weight management for remission of type 2 diabetes (DiRECT trial).
    The Lancet, 391(10120), 541–551.

11. Taylor, R. (2013).
    Type 2 diabetes: etiology and reversibility.
    Diabetes Care, 36(4), 1047–1055.

12. Ried-Larsen, M., et al. (2019).
    Type 2 diabetes remission through lifestyle intervention.
    Diabetes, Obesity and Metabolism, 21(3), 739–745.

Lifestyle, Exercise & Brain Protection

13. Erickson, K. I., et al. (2011).
    Exercise training increases size of hippocampus and improves memory.
    Proceedings of the National Academy of Sciences, 108(7), 3017–3022.

14. Livingston, G., et al. (2020).
    Dementia prevention, intervention, and care.
    The Lancet, 396(10248), 413–446.