Personalised Content. Daily Newsletters Sign Up

Can Alzheimer’s disease be called type 3 diabetes? Know how they are connected

Diabetes, a chronic condition that affects millions of people, may have a connection with Alzheimer's disease. Unofficially known as type 3 diabetes, here is how the two are linked.
View All Images
Type 3 diabetes is not an official diagnosis. Image courtesy: Adobe Stock
Updated On: 14 Jan 2025, 05:45 pm IST
Medically Reviewed by

Chat with

Diabetes may affect the heart, kidneys, eyes, and feet. The condition, in which the blood glucose or blood sugar gets too high, may also have an impact on the brain. It may be connected to Alzheimer’s disease, which leads to a decline in thinking, memory, and learning. In fact, some researchers dubbed Alzheimer’s disease as “Type 3 diabetes.” According to them, in this kind of medical condition, the brain’s ability to use blood sugar and produce energy is impaired. The term may not be often used by doctors or those in the medical field but there is surely a link between the brain condition and diabetes.

What is type 3 diabetes?

Type 3 diabetes often appears in discussions about a hypothesised relationship between the insulin resistance in the brain and Alzheimer’s disease. American neuropathologist Suzanne M. de la Monte, and her team were the ones to first use the term Type 3 diabetes for Alzheimer’s, according to the American Psychological Association. The term type 3 diabetes was proposed for the brain disease due to the shared features among type 1 and type 2 diabetes and insulin resistance associated with memory issues in elderly people, as per research published in Biochimica et Biophysica Acta – Molecular Basis of Disease 2017.

Know what type 3 diabetes is. Image courtesy: Adobe Stock

“Type 3 diabetes is not an official diagnosis, but some researchers consider Alzheimer’s as a new form of diabetes. In this condition, insulin resistance in neurons would lead to the failure in glucose metabolism and then to neurodegeneration,” says endocrinologist Dr Dheeraj Kapoor. This condition showcases the role played by insulin not in regulating blood sugars alone but also in cognitive performance, such as memory and learning.

What is the link between diabetes and Alzheimer’s disease?

“The connection between diabetes and Alzheimer’s disease is in insulin resistance and impaired glucose metabolism,” says the expert. In diabetes and Alzheimer’s, the ability of the brain to use glucose for energy is impaired. Systemic inflammation and oxidative stress, due to chronic hyperglycemia in diabetes, enhance the rate of amyloid plaque and tau tangle formation, the key features of Alzheimer’s. While amyloid plaques are clumps of protein formed between nerve cells in the brain, tau protein tangles are the abnormal accumulations of tau proteins in the brain.

“Insulin resistance, especially in the brain, could compromise neuronal function, which in turn can impair cognition,” says Dr Kapoor.

The link between the two conditions have often been studied by researchers. During a 2008 analysis, published in the Journal Of Diabetes Science And Technology, researchers found strong evidence in support of the hypothesis that Alzheimer’s disease represents a form of diabetes that selectively affects the brain.

What are the causes of type 3 diabetes?

  • Chronic insulin resistance: Insulin resistance, often associated with type 2 diabetes, may disrupt brain cells by exacerbating glucose utilisation.
  • Inflammation and oxidative stress: Systemic inflammation and oxidative stress directly destroy neurons and encourage the development of amyloid plaques and tau protein tangles.
  • Genetic susceptibility: “Variants of the apolipoprotein E gene are predisposed to a higher risk of Alzheimer’s and may contribute to insulin dysregulation in the brain,” says the expert.
  • Unhealthy lifestyle factors: Poor diets, physical inactivity, and obesity can intensify metabolic disorders, and in turn, increase the risk of central insulin resistance.
  • Cardiovascular factors: Hypertension or high blood pressure tend to compromise cerebral blood flow and interfere with glucose transport to neurons. A 2020 study, published in the International Journal Of Molecular Sciences, showed that high blood pressure played a role in the development of Alzheimer’s disease.

What are the symptoms of type 3 diabetes?

“The symptoms of type 3 diabetes are generally cognitive and neurological, reflecting poor function in the brain due to insulin resistance,” says the expert. Due to impaired glucose utilisation within the brain, you may notice symptoms such as:

  • Forgetfulness
  • Inability to learn new things
  • Confusion

“Since the glucose does not get utilised properly within the brain, it can lead to an energy deficit. This can disrupt synaptic communication used in memory and other cognitive processing functions,” says the expert.

As the disease progresses, people with type 3 diabetes may experience:

  • Poor judgement
  • Language difficulties
  • Loss of problem-solving ability

Mood changes are also common due to the changes in brain chemistry associated with insulin insufficiency,” says the expert.

In the later stages, symptoms include:

  • Severe memory loss
  • Confusion
  • An inability to carry out daily activities without any help.

How to diagnose type 3 diabetes?

Diagnosing type 3 diabetes is generally a combination of cognitive tests and medical tests. “There is no particular test for type 3 diabetes, but doctors check symptoms such as loss of memory, inability to concentrate, and mental decline,” says the expert. Blood tests to measure insulin levels and glucose metabolism, as well as imaging techniques such as Magnetic Resonance Imaging, can identify abnormalities in the brain associated with insulin resistance.

How to treat type 3 diabetes?

There is no official type 3 diabetes treatment but you can do the following:

1. Eat nutrient-dense diet

Eat foods like fruits, and vegetables that are rich in antioxidants to reduce oxidative stress and improve neuronal energy metabolism. “Fatty fish, nuts, and seeds contain omega-3 fatty acids that reduce inflammation and support cognitive function,” says the expert.

Maintain healthy weight. Image courtesy: Freepik

2. Start exercising

Regular physical activity enhances insulin sensitivity and improves brain health through increased cerebral blood flow. It can also help to prevent different types of diabetes. Maintaining moderate body weight and engaging in physical activity may help prevent diabetes, as per the US National Institute of Diabetes and Digestive and Kidney Diseases.

3. Medical interventions

They might include medications aimed at regulating insulin or therapies for the amyloid plaques. Metformin, a common diabetes drug, may help to improve cognitive performance, as per a study, published in Frontiers In Pharmacology in 2022. “There are also treatments such as intranasal delivery of insulin to normalise glucose metabolism in the brain,” says the expert.

Type 3 diabetes is not an official diagnosis, and is just a theory. But the connection with diabetes and Alzheimer’s disease cannot be ignored. It is believed that Alzheimer’s disease is connected to insulin resistance in the brain. It is best to eat healthy, engage in physical activity, and control high blood pressure to stay healthy.

Related FAQs

Can type 3 diabetes be reversed?

Reversing type 3 diabetes, often associated with insulin resistance in the brain, is a complex concept. The neurodegenerative process can't be easily reversed, although early intervention may slow down disease progression. Lifestyle changes would include a balanced diet rich in antioxidants and omega-3 fatty acids, regular physical exercise, and managing glucose levels as much as possible. Intranasal insulin delivery and medications against amyloid plaques may help to manage problems associated with cognitive decline.

Can type 3 diabetes kill you?

Type 3 diabetes in itself is not directly fatal, however, it is associated with cognitive decline and neurodegenerative conditions. This may pose a threat to the overall health and quality of life. With early diagnosis and proactive management, including lifestyle changes and medical interventions, complications may be significantly reduced, brain health promoted, and longevity enhanced with hope for a better outcome.

Disclaimer: At Health Shots, we are committed to providing accurate, reliable, and authentic information to support your health and well-being. However, the content on this website is intended solely for informational purposes and should not be considered a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider for personalised advice regarding your specific medical condition or concerns.

About the Author
Natalia Ningthoujam

Natalia Ningthoujam has written on various subjects - from music to films and fashion to lifestyle - as a journalist in her career that started in 2010. After getting stories from the crime scene, police headquarters, and conducting interviews with celebrities, she is now writing on health and wellness which has become her focus area.

Hi!
I am

Get AI-powered answers to all your health related queries!

Reproductive Care Self Care Chat Now
Next Story