The group of researchers from Brown University Medical School analyzed, in the frontal part of the brain, one of the major area affected by Alzheimer's, insulin and insulin receptor function.
The team discovered that the levels of insulin receptors and the brain's ability to respond to insulin decreased as the severity of Alzheimer's increased.
According to the experts, insulin receptors were nearly 80 per cent lower than in a normal brain in the most advanced stage of Alzheimer's.
Two abnormal situations related to insulin in Alzheimer's were also found by researchers.
The first abnormal situation was that as the disease progressed, levels of insulin dropped.
In relation to the second one, experts explained that insulin and its related protein, insulin-related growth factor-I, lose the ability to bind to cell receptors, which creates a resistance to the insulin growth factors, causing the cells to malfunction and die.
For the neuropathologist at Rhode Island Hospital and professor of pathology at Brown University Medical School, Suzanne M.
de la Monte, this means that they are able to show that insulin impairment happens early in the disease, as well as they are able to show it is linked to major neurotransmitters responsible for cognition.
"We're able to show it's linked to poor energy metabolism, and it's linked to abnormalities that contribute to the tangles characteristic of advanced Alzheimer's disease.
This work ties several concepts together and demonstrates that Alzheimer's disease is quite possibly a Type 3 diabetes", explains de la Monte, the leader of the research.