Some people use the term “type 3 diabetes” to describe Alzheimer’s disease. However, official health organizations do not accept this term, and most doctors do not use it for diagnostic purposes. Some scientists believe insulin resistance causes amyloid plaques, inflammation, and oxidative stress in the brain.

Although health associations do not classify type 3 as an official form of diabetes, insulin and glucose dysregulation makes it similar to other types, such as type 1 and type 2 diabetes.

However, type 3 diabetes involves the brain and leads to Alzheimer’s disease.

This article explains what type 3 diabetes is and how it links to Alzheimer’s disease. It discusses the possible causes and risk factors, along with treatment and prevention strategies.

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“Type 3 diabetes” is a term some people use to describe Alzheimer’s disease. Some scientists proposed the term because they believe insulin dysregulation in the brain causes dementia.

However, type 3 diabetes is not an officially recognized health condition. The American Diabetes Association, as well as other major health organizations, does not list Alzheimer’s disease as a type of diabetes within their classification.

Other types of diabetes include type 1, type 2, and gestational diabetes. In addition, some research uses the term “type 3c” to classify pancreatogenic diabetes that may result from pancreatitis. This type is different from Alzheimer’s disease.

Doctors do not use “type 3 diabetes” as a diagnostic term, because it is not an official classification. They can, however, diagnose Alzheimer’s disease using physical and mental tests, neurological exams, and brain imaging.

According to the Alzheimer’s Association, the early signs and symptoms of Alzheimer’s disease include:

  • memory loss that negatively impacts daily life
  • trouble resolving problems or making plans
  • difficulty carrying out familiar tasks
  • confusion about location or time
  • difficulty using and understanding written and spoken language
  • mislaying things
  • decreased judgment
  • withdrawal from social activities or work
  • mood and personality changes

It is important to note that some changes in memory and habits can be part of aging. However, if a person is concerned about any changes they are experiencing, they should seek guidance from a doctor.

Learn about the different stages of Alzheimer’s disease here.

Authors of a 2008 review conclude that the term “type 3 diabetes” accurately reflects the fact that Alzheimer’s disease is a form of diabetes that affects the brain. They used human and animal studies to explain how this happens.

They describe Alzheimer’s disease as a neuroendocrine disease involving impaired insulin and insulin-like growth factor (IGF) signaling. The condition can also involve inflammation and oxidative stress.

The authors note that while obesity and type 2 diabetes might contribute to the development of Alzheimer’s disease, they are not sufficient causes by themselves.

However, a more recent study suggests that insulin-degrading enzyme may shift type 2 diabetes to type 3 diabetes by altering metabolic pathways. This process may result in oxidative stress and beta-amyloid in the brain, which are both characteristics of Alzheimer’s disease.

A 2020 study lists the potential risk factors for developing type 3 diabetes. These include:

  • a diet high in calories, sugar, and fat and low in fiber
  • low socioeconomic status
  • exposure to stress
  • race and ethnicity
  • lack of physical activity
  • genetics
  • family history
  • birth weight

The same study indicates that high blood pressure and impaired lipid, or fat, transportation play a role in the development of Alzheimer’s disease.

Additionally, having the APOE4 gene can increase a person’s risk of the condition.

There is no cure for type 3 diabetes (Alzheimer’s disease), but doctors may prescribe drugs to slow the progression of the condition or treat its symptoms.

Changing disease progression

Aducanumab is an anti-myloid antibody drug that may help reduce cognitive and functional decline in people in the early stages of Alzheimer’s disease.

Treating symptoms

Medications that can lessen memory loss and thinking issues in Alzheimer’s disease include donepezil and galantamine.

Drugs that may improve behavioral and psychological symptoms include suvorexant, which may help prevent insomnia.

Additionally, some people use alternative and natural treatments. However, the Alzheimer’s Association notes that these may not be effective or safe.

According to the National Institute on Aging, there is encouraging, although inconclusive, evidence that the following may help prevent or delay type 3 diabetes (Alzheimer’s disease) and cognitive decline:

There is also no definite evidence concerning dietary therapies for Alzheimer’s disease prevention.

Some research has explored curcumin, a ketogenic diet, and antioxidants as potential therapeutic agents, but so far, studies have been inconclusive.

The National Institute of Diabetes and Digestive and Kidney Diseases advises that reaching or maintaining moderate body weight and engaging in enough physical activity may help prevent insulin resistance and prediabetes.

Although scientists have not proven the effectiveness of any strategies for avoiding Alzheimer’s disease, managing blood glucose may be a sensible approach.

A doctor may also prescribe metformin to delay the onset of or treat diabetes.

Learn about the symptoms of early onset Alzheimer’s disease here.

There are fundamental differences between type 3 diabetes (Alzheimer’s disease) and type 1 and type 2 diabetes. Alzheimer’s disease is an entirely separate condition.

In the following table, we compare diabetes types 1, 2, and 3.

Type 1 diabetesType 2 diabetesType 3 diabetes (Alzheimer’s disease)
What is happening?The body attacks the cells in the pancreas, which causes them to lose the ability to make insulin.The body does not use insulin well or cannot make enough to keep up with the demand.The body experiences impaired insulin and IGF signaling, oxidative stress, and inflammation.
Risk factors and causesScientists currently do not know the exact cause of type 1 diabetes, but genes or viruses may trigger it.Overweight, obesity, and physical inactivity may lead to type 2 diabetes.Possible risk factors are poor diet, obesity, type 2 diabetes, inactivity, genes, ethnicity, and high blood pressure.
Management Management involves insulin medications, such as metformin.Medication, diet, and exercise may help people with type 2 diabetes.Management of Alzheimer’s disease involves medications and support. People can manage blood sugar through diet and lifestyle.
Treatment and preventionThere is no cure, but medication can help manage the condition. Studies on prevention are ongoing.Lifestyle and dietary changes can help treat and prevent type 2 diabetes.Treatment of Alzheimer’s disease involves medication, although there is no cure. Physical activity, a healthy diet, and a moderate body weight can help prevent insulin resistance.

Learn more about the differences between type 1 and type 2 diabetes here.

There is no cure for type 3 diabetes (Alzheimer’s disease). However, there are many treatment options available that may lessen the severity of symptoms and prolong a person’s life.

Some people with Alzheimer’s disease will not develop symptoms for years, although this can vary from person to person.

Most people with Alzheimer’s disease will die from another cause. However, since Alzheimer’s disease causes neurological problems, it could lead to:

People with Alzheimer’s disease may require palliative care to improve their quality of life in the final stages of the condition.

Learn more about palliative care and hospice care here.

“Type 3 diabetes” is a term some people use to describe Alzheimer’s disease, but major health organizations do not recognize it as a type of diabetes in their classifications.

Scientists believe that insulin resistance in the brain can lead to the characteristic symptoms of Alzheimer’s disease, such as amyloid plaques, oxidative stress, and inflammation.

While researchers have called for more studies, they acknowledge that some factors seem to increase the risk of developing Alzheimer’s disease. These include overweight, little physical activity, and high blood pressure.

People can use diet and lifestyle changes to manage their weight and blood sugar, which may play a role in preventing cognitive decline.