Is there a link between Diabetes and Dementia?
There is a link between diabetes and dementia. People with type 2 diabetes are more likely to experience cognitive impairment, including Alzheimer’s disease and vascular dementia. (Cognitive impairment refers to various issues, such as trouble concentrating, learning new things, remembering information, and making decisions.)
Also, the younger someone is when they develop diabetes, the higher their risk of developing dementia.
Global Diabetes Prevalence
The global diabetes prevalence in 2019 was 9.3%, or 463 million people. Experts expect it to rise to 10.2%, or 578 million people, by 2030.
Various theories to how type 2 diabetes could lead to dementia
As per an article of MedicalNewsToday, the various theories to how type 2 diabetes could lead to dementia:
- Diabetes affects the heart. Heart disease and increased blood pressure can increase the risk of stroke, which can lead to dementia. However, strokes alone do not fully explain the association, as some research shows that diabetes can increase the risk of of dementia without a history of stroke.
- Chronic diabetes leads to the narrowing of the small arteries and capillaries that deliver fresh oxygen and nutrition throughout the body, including the brain. Together with high blood pressure and elevated lipids — both of which are common in people with diabetes — this can lead to cerebrovascular damage, which might increase the risk of vascular dementia.
- Hypoglycemia or low blood sugar may contribute. Controlling blood sugar typically reduces the long-term risks of heart disease and stroke, but it may also lead to memory loss and dementia. A potential reason is that low blood sugar damages the hippocampus, which plays a role in memory.
- Another theory is that diabetes directly causes Alzheimer’s disease. It seems that insulin plays a critical role in forming amyloid plaques. Research suggests that high blood sugar levels can lead to an increase in beta-amyloid, a protein that occurs naturally in the brain. Beta-amyloid is a sticky substance, and abnormal levels can lead to it forming clumps or plaques. These plaques are a hallmark of Alzheimer’s disease.
Diabetes & Dementia - Life Expectancy
Having both conditions appears to shorten life expectancy. A 2019 study linked diabetes with a higher dementia and mortality risk. During the 12-year follow-up of 8,328 participants, the researchers associated diabetes with an increased risk of dementia and a lower dementia-free life expectancy. Dementia-free life expectancy for a 70-year-old with diabetes was 13.4 years for females and 16.1 years for males. Among those without the condition, the results were 16.5 years and 19.6 years for females and males, respectively.
Though there are no proven ways to prevent dementia, a person can reduce their risk of diabetes (and hence dementia) by following a healthy lifestyle.