Patients with Alzheimer's disease could be offered new treatments after scientists demonstrated the beneficial effect of insulin on the brain.
The discovery has raised hopes that diabetes drugs could be developed as treatments for Alzheimer's, and boosted theories that the disease - characterised by progressively catastrophic dementia - could be due to a type of brain diabetes.
A US-led research team found that the hormone insulin, which is released by the pancreas to help control levels of sugar in the blood, protected memory-forming parts of the brain.
The team of researchers from Northwestern University in Illinois and the Federal University of Rio de Janeiro in Brazil concluded that insulin may slow or prevent the memory loss caused by toxic proteins which attack the brains of Alzheimer's sufferers.
Researcher Sergio Ferreira, a professor of biochemistry in Rio de Janeiro, said: "Recognising that Alzheimer's disease is a type of brain diabetes points the way to novel discoveries that may finally result in disease-modifying treatments for this devastating disease."
People with diabetes either fail to produce insulin, do not produce enough or fail to use what they do produce effectively.
The study was published in the Proceedings of the National Academy of Sciences.