Researchers in the US found that insulin can protect neurons from the toxic proteins present in the brains of people with Alzheimer's disease.
The study suggests insulin and diabetes drugs could therefore be used to prevent memory loss and dementia in the 700,000 people in the UK who suffer from Alzheimer's disease.
The research adds weight to previous theories that the condition may be a third form of diabetes.
What is the research?
Severe memory loss in Alzheimer's patients is thought to be caused by build-up of beta-amyloid plaques, which cause structural damage to synapses in the brain.
Using mature cultures of hippocampal neurons, researchers found insulin protected these synapses from damage during a three-hour exposure to beta-amyloid.
The study also found the insulin-sensitising drug rosiglitazone increased the protective effect of low levels of insulin, suggesting that insulin plays a crucial role in brain function.
The researchers concluded that boosting patients' insulin levels could protect the central nervous system from the neurotoxins associated with Alzheimer's disease.
What do the researchers say?
The study was conducted by teams from Northwestern University in Illinois and the Federal University of Rio de Janeiro in Brazil.
Senior author Professor William L Klein said therapies designed to increase insulin sensitivity in the brain could provide new treatments for Alzheimer's. 'Sensitivity to insulin can decline with ageing, which presents a novel risk factor for Alzheimer's disease. Our results demonstrate that bolstering insulin signalling can protect neurons from harm.'
Co-author Professor Fernanda De Felice said the discovery offered 'new hope for fighting memory loss in Alzheimer's disease'.
What do other researchers say?
Rebecca Wood, chief executive of the Alzheimer's Research Trust, agreed that the findings, alongside existing research, could lead to new avenues for treating Alzheimer's disease with diabetes drugs.
'People with diabetes are at higher risk of developing Alzheimer's,' she said. 'This research adds more evidence to the possibility that Alzheimer's could be a type of brain diabetes.
'The most exciting implications are that some diabetes drugs have the potential to be developed as Alzheimer's treatments.
'The Alzheimer's Research Trust is also funding work looking at how insulin acts on the brain, and we hope this will lead to new treatments.'