The Diabetes-Alzheimer's Connection: New Research Explains the Link

Scientists discovered specific protein changes in the brains of people with both diabetes and Alzheimer's, helping explain why diabetes increases dementia risk.

Scientists have long observed that people with type 2 diabetes face a higher risk of developing Alzheimer's disease, leading some researchers to call Alzheimer's "type 3 diabetes." But why? A new study published in Alzheimer's & Dementia helps explain this connection at the molecular level.

Why Alzheimer's Is Sometimes Called "Type 3 Diabetes"

The term "type 3 diabetes" came about because researchers noticed that Alzheimer's disease shares several features with diabetes:

• Both conditions show problems with insulin signaling
• The brain's ability to use glucose becomes impaired
• Similar molecular pathways are affected

The brain usually depends heavily on insulin for proper function. In both diabetes and Alzheimer's, this insulin signaling goes awry, affecting how brain cells communicate and survive.

What the New Research Found

Researchers examined brain tissue from 191 older adults, some with diabetes, some with Alzheimer's, some with both conditions, and some with neither. They found:

1. Specific protein changes (phosphorylation) occur differently in people with both conditions
2. A protein called tau, already known to be important in Alzheimer's, shows unique patterns of modification in people with diabetes
3. Networks of protein changes suggest diabetes and Alzheimer's work together to damage brain cells

Real-World Implications This research matters because:

• It helps explain why controlling diabetes might help prevent dementia
• It identifies specific molecular targets for future treatments
• It suggests that treating diabetes early might help protect brain health
• It opens new avenues for developing drugs that could treat both conditions

The Details

• Scientists found that a brain protein called tau gets modified differently in people with diabetes, showing a direct molecular link between diabetes and brain changes typical in Alzheimer's disease.
• Among 191 brain samples studied, researchers identified 7,874 protein modification sites that help explain how diabetes and Alzheimer's disease interact at the molecular level.
• The study discovered two major groups of protein changes (PM-7 and PM-11) that directly correlate with both cognitive decline and blood sugar control.
• Researchers mapped specific protein modifications to exact locations in the brain and showed how these changes track with cognitive test scores, blood sugar levels, and other clinical measures.
• In people with both diabetes and Alzheimer's disease, the research team found distinct patterns of protein changes in astrocytes (brain support cells), suggesting diabetes might affect brain health through multiple pathways.

What This Means for You

If you have diabetes, this research reinforces the importance of good blood sugar control for brain health. It also suggests that:

• Managing diabetes well may help protect your brain
• Early diabetes treatment might be even more important than previously thought
• Future treatments might target both conditions simultaneously

Read the full research paper here

This research represents a step forward in understanding how diabetes affects brain health. As we better understand these connections, we move closer to developing more effective treatments for both conditions.

Remember: While this research is promising, maintaining a healthy lifestyle, controlling blood sugar remains the best strategy for protecting both body and brain health.

What's Next? Researchers will likely use these findings to:

• Develop new medications targeting the identified protein changes
• Create better ways to identify people at risk
• Design preventive strategies for people with diabetes