Can High Blood Sugar Increase Your Risk of Alzheimer’s Disease?
We typically think of high blood sugar in terms of diabetes — but what if it also affected your brain?
Emerging research shows a strong link between chronically elevated blood sugar and increased risk of Alzheimer’s disease. In fact, some scientists now refer to Alzheimer’s as “Type 3 diabetes” due to the way insulin resistance impacts brain function.
What’s the Connection Between Blood Sugar and Brain Health?
Your brain depends on glucose as its main energy source. But when blood sugar is consistently high — due to poor diet, insulin resistance, or diabetes — it can disrupt the brain’s ability to use that energy effectively.
This can lead to:
- Inflammation and oxidative stress
- Reduced blood flow to brain tissue
- Damage to neurons and synapses
- Increased beta-amyloid buildup, a key marker of Alzheimer’s
A study published in Neurology found that people with poor blood sugar control performed worse on memory tests and had a faster rate of cognitive decline.
Is Diabetes a Risk Factor for Alzheimer’s?
Yes. People with type 2 diabetes have up to a 50% higher risk of developing dementia. The longer someone has diabetes — and the less controlled it is — the greater the risk appears to be.
Even individuals with pre-diabetes or consistently high blood sugar (without a formal diagnosis) may be more vulnerable.
How to Lower Your Risk
The good news is that blood sugar is a modifiable risk factor. You can protect your brain by:
- Eating a low-glycemic diet rich in whole grains, leafy greens, and healthy fats
- Getting regular aerobic exercise, which improves insulin sensitivity
- Monitoring glucose levels if you’re at risk or over 50
- Managing weight, stress, and sleep — all of which impact insulin response
Final Thoughts
Managing blood sugar isn't just about preventing diabetes — it could be one of the smartest moves you make for your brain. Whether or not you’ve been diagnosed with diabetes, keeping your glucose levels stable may lower your risk of Alzheimer’s and support long-term cognitive health.