Understanding the connection

Diabetes can cause several complications, such as damage to your blood vessels. Diabetes is considered a risk factor for vascular dementia. This type of dementia occurs due to brain damage that is often caused by reduced or blocked blood flow to your brain.

Many people with diabetes have brain changes that are hallmarks of both Alzheimer's disease and vascular dementia. Some researchers think that each condition fuels the damage caused by the other.

Ongoing research is aimed at trying to better understand the link between Alzheimer's and diabetes. That link may occur as a result of the complex ways that type 2 diabetes affects the ability of the brain and other body tissues to use sugar (glucose) and respond to insulin.

Diabetes may also increase the risk of developing mild cognitive impairment (MCI), a condition in which people experience more thinking (cognitive) and memory problems than are usually present in normal aging. Some research indicates that diabetes may increase the risk of MCI worsening to dementia. Mild cognitive impairment may precede or accompany Alzheimer's disease and other types of dementia.

As researchers examine the connections between diabetes and Alzheimer's, they're also studying potential ways to prevent or treat both diseases. But a recent trial of intranasal insulin showed no cognitive benefit.