You might hear talk that diabetes is linked to an increased risk for dementia. What do you know about this subject? Can you define the term dementia? Do you know when you should discuss possible dementia with your doctor?  This blog will explain what dementia is and follow with recent research on diabetes and dementia. A link will be provided for you to see the names of studies on dementia that have been completed as well as those that are still recruiting subjects.

What does the term “dementia” actually mean?

According to the National Institute of Neurological Disorders and Stroke (NINDS) which is part of the National Institutes of Health (NIH), dementia is not one specific disease.  Dementia affects the brain and causes problems with intellectual functioning.

Examples of these changes include loss of:

  • Problem solving abilities
  • Emotional control

These changes can lead to personality changes. Some people with dementia experience frustration, delusions and agitation. The diagnosis of dementia often includes memory loss but memory loss alone is not enough to diagnose dementia.  Technically, two different functions of the brain need to be affected for a doctor to give the diagnosis. The example given by the NINDS is memory and language skills.

Examples of diseases that cause dementia include:

  • Alzheimer’s Disease
  • Vascular Dementia
  • Huntington’s Disease


There are problems that also cause dementia which if caught early may be reversible. These include reactions to medications, thyroid imbalance, deficiency or lack of absorption of vitamins such as B12 and thiamine, and for people with diabetes, repeated episodes of hypoglycemia. Here is a detailed list of potential metabolic problems that can cause symptoms of dementia that may lead to dementia itself. Dementia should not be thought of as part of a normal aging process. (2)

When should you ask your doctor if something is potentially wrong?

The Joint Commission (an agency that certifies many health care organizations in the United States), has an excellent brochure on memory problems and dementia. Information includes when you should be concerned about memory, what your doctor will do, what should you or your advocate ask the doctor, and what to ask your doctor if you are told you have dementia.

What is the relationship between blood glucose and dementia?

Results of a large study published by the New England Journal of Medicine in 2013 evaluated glucose levels and hemoglobin A1C values from 2,067 individuals with dementia. The study explored the risk of dementia and blood glucose.
Results of this study indicated that the risk of dementia increases as blood glucose levels increase. This is true even in people not diagnosed with diabetes but with average blood glucose values higher than 100 mg/dl. If a person had average blood glucose of 115 mg/dl their risk for dementia was 18 percent higher than those with average blood glucose of 100 mg/dl. People that had diabetes had increased risk of dementia as their average blood glucose increased. The example used was that people with average blood glucose of 160 mg/dl had a 40 lower risk of developing dementia than those with an average glucose level of 190 mg/dl.

A person with type 2 diabetes has a greater risk of developing certain types of dementia including Alzheimer’s disease and vascular dementia due to shared cardiovascular issues. Alzheimer’s disease is sometimes referred to as Type 3 diabetes. In the brain of people with Alzheimer’s disease, the use of glucose is changed. It is theorized that the cause of this could be due to cell death or lack of oxygen to the brain.  Amyloid plaques in the brain are one of the hallmark signs of Alzheimer’s disease. They are made of proteins that are not folded correctly. Amyloid plaques may cause brain cells to decrease their sensitivity to insulin. (3)

A study published in 2014 of over 29,000 patients with diabetes concluded that if severe retinal disease was diagnosed at baseline they were at a 42 percent increased risk for developing dementia. The authors of the study also mentioned the relationship between hypertension and inversely low blood pressure, high cholesterol as well as a history of severe hypoglycemia. (4)

Recommendations for people with diabetes to reduce their risk of dementia

It is recommended to reduce the risk of dementia, to keep glucose levels under control.  It is also recommended that people exercise their minds and bodies to help prevent dementia for people with diabetes. Other recommendations include following a meal plan that meets all nutritional needs (if in question get help from your dietitian). (3) For people taking the medication metformin, have vitamin B12 levels evaluated periodically can help avoid deficiency of vitamin B12. (5) People taking metformin have an increased risk of low vitamin B12 levels.

It is very important to see the relationship between diabetes and dementia and take action to managing blood glucose values. As you can read in this blog, both high blood glucose values and very low blood glucose values are risk factors for dementia. Other aspects that are related to diabetes such as hypertension and also hypotension should also be controlled.

If a loved one has developed dementia and/or you are interested in learning about clinical trials, go to We at want you to take the best possible care of yourself!