Scientists have long studied Alzheimer’s disease as a condition involving memory loss and changes in brain structure. But newer research suggests there may also be a metabolic side to the illness, meaning the Alzheimer’s brain may struggle to use energy the way it should. Some researchers call this potential overlap “type 3 diabetes.” 

In the review published in Cells, researchers explain that the brains of people with Alzheimer’s show signs of insulin resistance. Most of us think of insulin as the hormone that helps manage blood sugar, but the brain uses insulin too. It helps nerve cells take in glucose, which is their main source of fuel. 

When brain cells stop responding to insulin properly, they may not get the energy they need to function. Over time, this lack of fuel could contribute to memory problems and confusion. 

Key Takeaways from the Study 

• Brain energy use is disrupted. Neurons in Alzheimer’s may have trouble using glucose, even when the rest of the body handles it normally. 

• Insulin resistance may worsen Alzheimer’s changes. Poor insulin signaling appears to encourage the buildup of amyloid plaques and tau tangles – the proteins closely linked to Alzheimer’s. 

• Inflammation may increase. Insulin problems in the brain can trigger harmful inflammatory processes. 

• Shared pathways with diabetes. Several molecular pathways that break down in type 2 diabetes also malfunction in Alzheimer’s. 

Why This Matters 

Viewing Alzheimer’s partly as a metabolic issue could lead to new treatment approaches, including therapies that improve insulin sensitivity. While more research is needed, this perspective emphasizes something encouraging: supporting our overall metabolic health by staying active, eating well, and managing blood sugar, may also support long-term brain health.