Why diabetic patients are more likely to develop Alzheimer’s disease has not been understood. Researchers believe they may have identified the diabetes – Alzheimer’s connection.

David R. Schubert, PhD, professor Cellular Neurobiology Laboratory, Salk Institute for Biological Studies, reports that blood vessels in the brain of young diabetic mice are damaged by the interaction of elevated blood glucose levels characteristic of diabetes and low levels of beta amyloid (a peptide that clumps to form a plaque in the brain associated with Alzheimer’s).

Recent studies show that both type 1 & 2 diabetic patients have a 30-65% higher risk of developing Alzheimer’s disease compared to non-diabetic individuals. Most previous studies investigating the diabetes-Alzheimer’s connection have focused on altered insulin signaling in the brain, but have paid little attention to the effects of increased blood glucose levels on brain function and the role they play in development of Alzheimer’s.

Using genetically engineered mice researchers found that vascular damage was due to overproduction of free radicals, which damage the cells lining the brain’s blood vessels. There may be a synergistic toxicity between the amyloid protein and a high level of blood glucose that is causing problems with blood vessel formation.

While this initial trial was only marginally successful a new family of drugs has shown promise for preventing Alzheimer’s disease and perhaps the vascular damage associated with diabetes.