Diabetes of the Brain: How Diabetes Affects the Brain

Diabetes of the brain refers to how diabetes affects the brain. Learn about the link between diabetes and brain damage and how you can improve it on HealthyPlace.

Diabetes of the brain, sometimes called type 3 diabetes, is a nickname occasionally used to describe Alzheimer’s disease, a type of dementia that involves significant cognitive decline and progressively worsens over time. While diabetes of the brain isn’t an official diagnosis or medical term, it does highlight the connection between the disease and the brain ("Diabetes and Dementia: Can Diabetes Lead to Alzheimer’s Disease?"). While much has yet to be discovered, researchers have demonstrated that diabetes affects the brain, usually in harmful, damaging ways.

Ongoing research studies seek to determine how diabetes affects the brain ("How Diabetes Causes Brain Fog and Memory Loss: Can Anything Help?"). While many questions remain unanswered, thus far studies implicate diabetes in damage to the brain. Quoting researcher Zhanjun Zhang, MD, Schieszer (2015) explains that, “All these studies draw us a definite and defined conclusion that type 2 diabetes destroys the central nervous system, especially in the brain.”

Let’s look at how diabetes affects the brain, both structure and function.

Diabetes and the Brain: Changes and Damage

Understanding the nature of diabetes can shed light on what goes wrong in the brain.

  • When the body digests food, one of the byproducts is glucose, or sugar.
  • Glucose enters the bloodstream and travels around the body to enter cells and provide energy.
  • The hormone insulin is supposed to escort glucose into the cells of the body, but in diabetes, either the body doesn’t make insulin (type 1) or it doesn’t make enough or use it efficiently (type 2).
  • Glucose remains in the bloodstream, building too high. This high blood sugar is called hyperglycemia. It damages blood vessels, nerves, and causes extensive damage.
  • Sometimes blood sugar drops too low, a condition called hypoglycemia. This is dangerous, too.

Problems with insulin and glucose help explain how diabetes affects the brain. Glucose is the brain’s main energy source, and both hyper- and hypoglycemia can cause harm. When this sugar is stuck in the bloodstream, it can’t nourish the brain.  It becomes starved of oxygen and nutrients, which compromise physical structures, hormones, and cognitive functioning. Chronic hyperglycemia stresses the brain, damages nerve cells, and harms both large and small blood vessels.

In diabetes, brain damage can be extensive, affecting areas such as the:

  • Hippocampus (volume reduced by four percent; Schieszer, 2015)
  • Amygdala
  • Cerebral cortex
  • Temporal lobe
  • Frontal lobe
  • Precuneus

Other casualties of diabetes include:

  • Atrophy
  • Reduced total brain volume (by almost three percent; Schieszer, 2015)
  • Changes in white matter
  • Loss of density in gray matter
  • Loss of brain cells
  • Changes in the connections and communication pathways between different regions in the brain, decreasing efficiency

While both type 1 diabetes and type 2 diabetes can affect the brain, type 2 diabetes is implicated more. Professionals speculate that this is linked to the cardiovascular problems accompanying type 2. Because of overweight or obesity and a sedentary lifestyle, people with diabetes type 2 often develop cardiovascular disease, high blood pressure, and high cholesterol. These also impact brain health, and when combined with hyper- and hypoglycemia, can further damage structures.

In addition to wreaking havoc on brain structures, does diabetes affect brain function? It absolutely can. Functioning deficits are effects of structural damage.

Symptoms of Brain Damage from Diabetes

Injury to brain structures, lost density, and other negative changes cause a decline in cognitive functioning. Sometimes people think of this deterioration as symptoms of diabetes-induced brain damage because they can be observed and measured.

Decreased executive functioning interferes in the ability to plan, organize, focus, and concentrate. Thinking can become rigid and inflexible. Memory declines, as does the ability to monitor thoughts and emotions and maintain self-control.

Perhaps surprisingly, these negative effects of diabetes and brain function aren’t inevitable. A 2017 study examined children with type 1 diabetes (Sukel). It’s logical to assume that diabetes also harms the brains of kids. It can and often does. But this study found that these children actually had improved cognitive functioning and increased connectivity between brain regions.

This is an encouraging indication that the brain is resilient and can heal. It needs help, though.

Controlling Diabetes and Brain Health

The best way to treat brain damage from diabetes is to prevent it from developing. That said, if you or a loved one lives with diabetes and has begun to experience cognitive decline, it’s possible to stop its progression.

The best way to prevent problems or improve brain health and diabetes is through lifestyle changes such as:

  • Losing weight if needed
  • Maintaining your weight once you’ve reached a healthy level
  • Eating nutritiously
  • Avoiding processed foods and sugar
  • Keeping alcohol consumption to a minimum
  • Stopping smoking if you smoke
  • Increasing physical activity and regular exercise

These actions are all important choices for a healthy brain and body. Controlling diabetes can minimize the damage that is nicknamed “diabetes of the brain” and keep you mentally sharp.

article references

APA Reference
Peterson, T. (2022, January 4). Diabetes of the Brain: How Diabetes Affects the Brain, HealthyPlace. Retrieved on 2024, June 24 from

Last Updated: January 12, 2022

Medically reviewed by Harry Croft, MD

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