Type 3 diabetes is a controversial name sometimes used to refer to Alzheimer’s disease, a type of progressive dementia. Strong links have been made between the two conditions, most notably that dementia may be triggered by a type of insulin resistance occurring specifically in the brain.
According to the American Diabetes Association (ADA), aside from advanced age having diabetes or prediabetes is the second biggest risk factor for Alzheimer’s disease.1
Arvanitakis Z, Wilson RS, Bienias JL, Evans DA, Bennett DA. Diabetes mellitus and risk of Alzheimer disease and decline in cognitive function. Arch Neurol. 2004;61(5):661-6. doi:10.1001/archneur.61.5.661 Although a small amount of research found an increased risk of dementia with type 1 diabetes, the vast majority of studies have concluded that this link between diabetes and Alzheimer’s is specific to type 2 diabetes.
However, classifying Alzheimer’s as type 3 diabetes is controversial, and many in the medical community are unwilling to recognize type 3 diabetes as a medical diagnosis until more research is done.