Type 2 Diabetes and Alzheimer’s disease
Amyloid deposits are always present in the affected tissues in two extremely common and important diseases: the pancreatic islets in type 2 diabetes and the brain in Alzheimer’s disease. But it is not known whether these amyloid deposits actually cause disease, whether they make it worse or even whether they are innocent. It is therefore wrong at this time to consider these two major conditions as forms of amyloidosis. However amyloid deposits are damaging everywhere else in the body and it is therefore likely that they are also not good for the pancreas and the brain. The evidence from experimental and clinical observations strongly suggests that islet amyloid deposits contribute to the severity and progression of type 2 diabetes. The protein that forms the amyloid deposits in Alzheimer’s, is definitely closely related to the cause of dementia because mutations which affect its production and structure cause hereditary early onset dementia. However, this does not prove that the actual amyloid deposits are themselves harmful. Only when treatments are available which eliminate these amyloid deposits will it be possible to know for sure whether and how they contribute to diabetes and dementia respectively.