Neurological Insights: Exploring the link between Type 3 Diabetes and Cognitive Health

Neurological Insights: Exploring the link between Type 3 Diabetes and Cognitive Health

Type 3 Diabetes and Cognitive Health represents an emerging area of research that investigates the connection between metabolic disorders, specifically diabetes, and cognitive function. While traditionally associated with insulin resistance and glucose dysregulation, diabetes is now being investigated for its potential impact on neurological health.

Is Alzheimer's a Type 3 Diabetes?

The concept of Alzheimer's disease being referred to as "Type 3 Diabetes" is a topic of scientific discussion, and it's not a universally accepted term. It is a widely used term to describe the potential link between insulin resistance in the brain and cognitive decline, particularly in conditions such as Alzheimer's disease. This concept suggests that disruptions in insulin signaling within the brain may lead to the development of neurodegenerative disorders, influencing cognitive functions

The connection between Type 3 diabetes and the Alzheimer's gene APOE has been explored in a recent investigation led by a Mayo Clinic neuroscientist. The study reveals that the APOE4 variant, present in around 20% of the general population and over half of Alzheimer's cases, disrupts the brain's insulin processing. Mice carrying the APOE4 gene exhibited impaired insulin function, particularly in old age. Additionally, a high-fat diet accelerated this process in middle-aged mice with the gene.

Insulin Resistance and Its Impact on the Brain

Insulin Resistance and Its Impact on the Brain

After insulin is secreted from pancreatic β-cells, it enters the brain through two distinct mechanisms - bypassing the Blood-Brain Barrier (BBB) via the median eminence and traversing the vascular endothelium facilitated by transport proteins. The process of insulin transportation into the brain is meticulously regulated and can undergo modifications in various physiological states, including obesity, diabetes mellitus, fasting, and Alzheimer's disease (AD).

According to a research article published in the American Journal of Physiology, insulin's penetration into the brain plays a pivotal role in regulating essential central nervous system functions like feeding, cognitive behavior, and addressing depression. Additionally, it functions in the brain to oversee broader systemic activities, including hepatic glucose production, lipolysis, lipogenesis, reproductive competence, and the sympathoadrenal response to hypoglycemia

Instances of reduced brain insulin action, termed brain insulin resistance, are observable in conditions such as obesity, type 2 diabetes (T2DM), aging, and Alzheimer's disease (AD). This suggests a potential correlation between metabolic and cognitive well-being.

The connection between T3D and Alzheimer's Disease (AD) is established on the foundation of disrupted glucose metabolism and its reliance on pathways associated with cell death, illustrated. In the context of T3D, neurons in the brain lose their responsiveness to insulin, a crucial factor for fundamental cognitive functions such as memory and learning.

What does research say about Diabetes Type 3?

Emerging research indicates that individuals with Alzheimer's disease exhibit a diabetic state in their brains. This is attributed to a reduction in insulin levels or insensitivity to insulin. Intriguingly, parallels exist between the brains of individuals with diabetes and those with Alzheimer's disease. It's important to note that while diabetes serves as a risk factor, it doesn't guarantee the development of dementia.

A research article published in Sage Journal infers that the term diabetes type 3 aptly captures the essence that Alzheimer's disease constitutes a Type of Diabetes specifically impacting the brain. This characterization aligns with molecular and biochemical characteristics that share commonalities with type 1 diabetes mellitus and type 2 diabetes mellitus (T2DM).

Another research says that since the initiation and progression of Alzheimer's disease are linked to Disruptions in Glucose Metabolism and impacting the regulation of the energy source ATP, it appears reasonable to categorize Alzheimer's disease as diabetes type 3.


  1. What is Type 3 Diabetes?

    Type 3 Diabetes refers to a proposed connection between insulin resistance and Alzheimer's disease. Some researchers suggest that insulin resistance in the brain may contribute to the development of Alzheimer's, leading to the conceptualization of Alzheimer's as a form of diabetes, often referred to as Type 3.

  2. What is diabetes type 3 caused by?

    Type 3 Diabetes is hypothesized to be caused by insulin resistance within the brain. This insulin resistance is believed to play a crucial role in the development and progression of Alzheimer's disease.

  3. How does Type 3 Diabetes differ from Type 1 and Type 2?

    Type 1 Diabetes is an autoimmune disease in which the body doesn't produce insulin. It is unrelated to insulin resistance and typically develops early in life. Type 2 Diabetes primarily involves insulin resistance, where the body's cells don't respond effectively to insulin. It often develops later in life and is associated with lifestyle factors. In contrast, Type 3 Diabetes is associated explicitly with Alzheimer's disease and its potential link to insulin resistance in the brain.

  4. What are the common Type 3 Diabetes symptoms?

    Symptoms of Type 3 Diabetes, referring to the link between insulin resistance and Alzheimer's, may include cognitive decline, memory loss, and other neurological impairments commonly associated with Alzheimer's disease.

  5. Can Type 3 Diabetes be reversed?

    The reversibility of Type 3 Diabetes, or the impact of managing insulin resistance on Alzheimer's progression, is an area of ongoing research. While some studies suggest that addressing insulin resistance through lifestyle changes may slow the progression of Alzheimer's, definitive evidence and a standardized approach are yet to be established. Early intervention and having a holistic approach to health are often emphasized in managing this condition.

Looking Ahead

The notion of diabetes type 3 arises from the connection between insulin resistance and Alzheimer's dementia in numerous instances, proposing it as an additional manifestation of diabetes. Its prognosis may depend on various factors, such as the diabetes treatment and the severity of dementia. The outlook would also depend on the timing of symptom discovery and the Healthcare Professionals assessment.