🧠 Is Alzheimer’s Really “Diabetes 3”?

catlaraba
Jun 22
2 min read

🧠 Is Alzheimer’s Really “Diabetes 3”?

Imagine Alzheimer’s not just as memory loss, but as insulin resistance in the brain. That’s why some researchers—and even institutions like the Mayo Clinic—have begun calling it “Type 3 diabetes.”

“Type 3 diabetes is a term used by some researchers to describe the theory that insulin resistance and insulin‑like growth factor dysfunction in the brain may cause Alzheimer’s disease.” (healthline.com)

Mayo Clinic neuroscientist Dr. Guojun Bu explains that people carrying the APOE4 gene—about 20% of the population—have brain cells that struggle with insulin, increasing Alzheimer's risk 10 to 15-fold. (newsnetwork.mayoclinic.org)

A landmark review concluded:

“We conclude that the term ‘type 3 diabetes’ accurately reflects the fact that AD represents a form of diabetes that selectively involves the brain.” (pmc.ncbi.nlm.nih.gov)

🔗 Blood Sugar & Alzheimer’s: What the Science Says

High blood sugar = faster brain aging: Even individuals without diabetes may experience accelerated brain shrinkage with elevated glucose levels (amenclinics.com).
Insulin resistance in the brain contributes to beta-amyloid build-up and neuronal energy failures (heart.org).
Chronic blood sugar spikes weaken the blood-brain barrier, fueling inflammation and oxidative stress tied to Alzheimer’s (eatingwell.com).

🧩 Can We Prevent “Type 3 Diabetes”?

While the link is still under study, growing evidence suggests early glucose control could protect brain health:

Dr. Narendra Kumar (Texas A&M) states:

“We think that diabetes and Alzheimer’s disease are strongly linked, and by taking preventative … measures for diabetes, we can prevent or at least significantly slow down … dementia in Alzheimer’s disease.” (news-medical.net)

The American Heart Association adds that glycemic control is very important for brain health—even extreme blood sugar swings double dementia risk (heart.org).

✅ Taking Action: Blood Sugar Smarts for Brain Health

Know your numbers: Aim for fasting blood glucose below 100 mg/dL; prediabetes (100–125 mg/dL) is a red flag (heart.org).
Adopt a brain-friendly diet:
- Follow Mediterranean or MIND principles—load up on leafy greens, berries, fatty fish, nuts, whole grains—and limit sugar and processed foods (eatingwell.com).
Get moving: Regular aerobic exercise boosts insulin sensitivity and reduces brain inflammation (amenclinics.com).
Monitor & manage: Work with a healthcare provider to watch blood sugar, lipids, blood pressure—and address prediabetes early .
Prioritize sleep & stress relief: Both factors impact insulin resistance and brain health (thetimes.co.uk).

🧭 Why This Matters

Alzheimer’s begins decades before symptoms appear, so early intervention is critical (stclair.org).
Labeling it “Type 3 diabetes” shifts the narrative: it’s not destiny—it’s a metabolic and lifestyle issue we can influence.
Managing blood sugar is not just about preventing diabetes—it’s also a potential strategy to preserve memory and clarity.