Insulin

In the brain, Insulin plays a key role in learning, memory, and neuron survival. When insulin resistance develops in brain cells (also known as type 3 diabetes), glucose cannot be used efficiently, leading to inflammation, cognitive decline, and progressive damage that mirrors patterns seen in diabetes.

Diet, blood sugar control, metabolic health, and lifestyle choices may influence brain aging more than previously believed. It suggests cognitive decline is not sudden or random, but connected to long term systemic health.

So its not Alzheimers and Dementia its type 3 diabetes