Type 2 diabetes and dementia
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A large number of people worldwide have diabetes mellitus, and according to studies, the number is expected to rise in the coming years.1 Type-2 diabetes is a condition where you show consistent high levels of blood glucose. You can develop it at any age but, it commonly occurs in middle-aged and older people.2

When diabetes is not controlled, the glucose in the blood starts increasing. Several studies have linked high levels of blood glucose to more significant risks of developing dementia.3 This article focuses on the association between type-2 diabetes and the risk of dementia.

What is dementia?

Dementia is a progressive disease comprising a wide range of specific medical conditions. The disorders under dementia are caused due to abnormal changes in the brain. These changes deteriorate the thinking ability of the person, which affects their routine activities, making them dependent on others for their personal activities.4 The leading causes of dementia are injuries and diseases. Vascular dementia and Alzheimer’s disease are the most common forms of dementia.5

The signs and symptoms of dementia are as follows:5

  • Short-term memory loss
  • Difficulty in communication
  • Disability in learning, calculation and comprehension
  • Needing assistance in personal care
  • Behavioural changes
  • Being unaware of time and place
  • Difficulty in walking

How does type-2 diabetes increase the risk of dementia?

Type-2 diabetes is associated with the accumulation of too much sugar in the blood, i.e., high blood glucose levels, which can affect the brain. This may lead to Alzheimer’s disease, a common cause of dementia in the later years.6

The possible pathophysiological mechanisms for how type-2 diabetes increases the risk of dementia are:6-8

  • Diabetes is a known risk for stroke. In combination with several other conditions that affect metabolism, type-2 diabetes can cause thickening of the membranes in the capillaries of the brain and make microvascular changes that eventually cause ischaemia of the brain (shortage of blood and oxygen supply). Ischaemia can cause cognitive impairment.
  • High blood glucose levels can cause inflammation that may damage the brain cells and cause Alzheimer’s disease.
  • Early stages of type 2 diabetes are associated with high levels of insulin in the blood. Excessive levels of insulin in the blood can accelerate cognitive impairment and cause dementia.

What is the treatment for dementia?

Currently, there is no specific treatment available to cure or stop the progress of dementia. However, through clinical trials, newer drugs are being investigated. Caregivers and family members can support and improve the lives of people with dementia. The primary goals of controlling the condition are early detection and treatment of the accompanying physical illness and behavioural symptoms.5

How will the doctor diagnose dementia and is it possible to prevent it in type-2 diabetes?

There is no specific test for dementia. However, doctors can diagnose the condition with the help of medical history, physical examination, laboratory tests and by examining characteristic changes in the thinking ability.4

Though research studies have not definitely shown a link between type-2 diabetes and the development of dementia, there has been evidence on how uncontrolled blood glucose levels and insulin can affect the delicate functioning of the brain. Hence maintaining healthy blood glucose levels may help reduce the risk of developing dementia.

The following changes to your lifestyle can help you to manage your blood glucose levels:2,3

  • Lose weight: Losing 5-7% of your body weight, if overweight, can prevent or delay the onset of
  • Eat the right diet: Cut down on the carbohydrates and sugary foods and eat the right portion size to control your intake.
  • Be physically active: Walk after your meals or take a brisk walk for at least 30 minutes on five days a week.8

Control your blood glucose levels and help keep away dementia and many other health concerns as well!


  1. Matioli MNPDS, Suemoto CK, Rodriguez RD, Farias DS, da Silva MM, Leite REP, et al. Association between diabetes and causes of dementia: Evidence from a clinicopathological study. Dement Neuropsychol. 2017 Oct-Dec;11(4):406-412.
  2. National Institute of Diabetes and Digestive and Kidney Diseases [Internet]. [updated 2017 May; cited 2019 Dec 19]. Available from: https://www.niddk.nih.gov/health-information/diabetes/overview/what-is-diabetes/type-2-diabetes.
  3. Harvard Health Publishing. Above-normal blood sugar linked to dementia [Internet]. [updated 2013 Aug 7; cited 2019 Dec 19]. Available from: https://www.health.harvard.edu/blog/above-normal-blood-sugar-linked-to-dementia-201308076596.
  4. Alzheimer’s Association. What is dementia? [Internet]. [cited 2019 Dec 19]. Available from: https://www.alz.org/alzheimers-dementia/what-is-dementia.
  5. World Health Organization. Dementia [Internet]. [updated 2019 Sep 19; cited 2019 Dec 19]. Available from: https://www.who.int/news-room/fact-sheets/detail/dementia.
  6. Alzheimer’s Association. Alzheimer’s disease and type-2 diabetes [Internet]. [cited 2019 Dec 19]. Available from: https://www.alz.org/national/documents/latino_brochure_diabetes.pdf.
  7. Biessels GJ, Staekenborg S, Brunner E, Brayne C, Scheltens P. Risk of dementia in diabetes mellitus: a systematic review. Lancet Neurol. 2006 Jan;5(1):64-74.
  8. Gudala K, Bansal D, Schifano F, Bhansali A. Diabetes mellitus and risk of dementia: a meta-analysis of prospective observational studies. J Diabetes Investig. 2013 Nov 27;4(6):640-650.

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