Is Diabetes Linked to Dementia?

Medical researchers suspect that type 2 diabetes is linked to the progression of dementia, and there is some evidence that Alzheimer’s may be caused by insulin resistance in the brain. This neuroendocrine phenomenon has been clinically described as type 3 diabetes, or T3D. The symptoms of type 3 diabetes mirror the symptoms of dementia, such as those seen in early Alzheimer’s disease.

However, the classification of type 3 diabetes remains controversial. It is not yet widely accepted in the medical field, as there are no clinical tests available to confirm the diagnosis. But the label is gaining traction as research continues to show a strong link between diabetes and dementia.

For example, a current study conducted by the National Institutes in Health confirms the implication that type 2 diabetes contributes to the progression of Alzheimer’s disease. Researchers identified the relationship to impaired insulin signaling in the brain. A recent study conducted by Mayo Clinic shows that a type of gene associated with dementia risk may interfere with the brain’s ability to use insulin. 

What Is Type 2 Diabetes?

Type 2 diabetes is a serious long-term condition in which the body is unable to use sugar or glucose efficiently. There are two mechanisms at work in the disease. First, the pancreas does not produce enough insulin, the hormone that allows sugar ( glucose) to be absorbed by the cells. Second, the cells respond poorly to the amount of insulin available, resulting in too much sugar in the blood. High blood sugar levels associated with diabetes can cause circulatory, nervous, or immune system disorders when left unchecked.

Symptoms of type 2 diabetes may include:

• Blurry vision
• Extreme fatigue
• Increased thirst
• Frequent urination
• Increased hunger
• Sudden weight loss
• Slow wound healing
• Tingling, pain, or numbness in extremities 

The American Diabetes Association states that individuals with type 2 diabetes are at a 60% greater risk for the development of dementia compared with those without diabetes. Women with diabetes are at a higher risk for vascular dementia than men. Researchers believe this is because chronic high blood sugar levels damage blood vessels, reducing blood flow to the brain, which causes injury to brain cells over time. Other scientists reason that insulin resistance causes amyloid plaques and inflammation in the brain, which are associated with a diagnosis of Alzheimer’s disease.

Scientists agree that advancements in identifying and treating type 3 diabetes are warranted.   

For now, there are many ways in which you can reduce your risk of developing type 2 diabetes and possibly dementia by making healthy lifestyle choices, such as

• Lose extra weight
• Quit smoking, or don’t start
• Increase physical activity, including aerobic and strength training
• Maintain a balanced diet of fruits, vegetables, and healthy fats
• Manage blood sugar levels with medication, if needed

Sources

“What is the link between Alzheimer’s and Type 3 diabetes?” Mayo Clinic. https://newsnetwork.mayoclinic.org/discussion/researchers-link-alzheimers-gene-to-type-iii-diabetes/ 

“Type 3 Diabetes and Its Role Implications in Alzheimer’s Disease”. National Library of Medicine. https://pmc.ncbi.nlm.nih.gov/articles/PMC7246646/ 

“Mayo Clinic Minute: Is Alzheimer’s Type 3 diabetes?” Mayo Clinic. https://newsnetwork.mayoclinic.org/discussion/mayo-clinic-minute-is-alzheimers-type-3-diabetes/ 

“Type 2 Diabetes”. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/type-2-diabetes/symptoms-causes/syc-20351193 

“Type 2 Diabetes as a Risk Factor for Dementia in Women Compared With Men: A Pooled Analysis of 2.3 Million People Comprising More Than 100,000 Cases of Dementia”. American Diabetes Association. https://diabetesjournals.org/care/article/39/2/300/37175/Type-2-Diabetes-as-a-Risk-Factor-for-Dementia-in