Is dementia more common in people with diabetes? Yes, research shows that people with diabetes face a higher risk of dementia and cognitive problems compared to those without it.
Diabetes affects the brain in several ways. High blood sugar over time can damage blood vessels, cause inflammation, and lead to insulin resistance in the brain. This makes it harder for brain cells to use glucose for energy, which harms memory and thinking skills. Studies find that diabetes doubles the chance of cognitive decline in older adults. For example, those with diabetes for more than five years have a much higher risk than people with shorter durations or good blood sugar control.
Meta-analyses confirm this link. People with diabetes have a 56 percent higher risk of Alzheimer’s disease and a 73 percent higher risk of all types of dementia than non-diabetics. The risk grows with poor blood sugar control, obesity, or vascular problems. Even prediabetes raises the odds of mild cognitive impairment.
Some experts call Alzheimer’s “type 3 diabetes” because of brain insulin resistance. In this idea, the brain struggles with insulin like the body does in type 2 diabetes. This leads to protein buildups, neuron damage, and worse memory, even without full diabetes. Up to 81 percent of Alzheimer’s patients show diabetes or prediabetes signs.
The connection works both ways. Diabetes harms the brain through high glucose and stress on cells. But cognitive issues can worsen diabetes by making it hard to stick to diets, take medicines, or check blood sugar. Longer diabetes duration speeds up this cycle.
Factors like nutrition, depression, and low mental activity also play a role in diabetics. Good blood sugar management and early checks can help lower the risk.
Sources
https://pmc.ncbi.nlm.nih.gov/articles/PMC12702780/
https://www.frontiersin.org/journals/dementia/articles/10.3389/frdem.2025.1730524/full
https://gulfnews.com/lifestyle/could-type-3-diabetes-harm-your-brain-what-your-blood-sugar-levels-mean-for-alzheimers-risk-1.500377397
https://www.wellmedhealthcare.com/patients/healthyliving/conditions-diseases/what-is-type-3-diabetes/
https://agsjournals.onlinelibrary.wiley.com/doi/10.1111/jgs.70231
https://pmc.ncbi.nlm.nih.gov/articles/PMC12726522/
