Tests showed it delayed the onset of Alzheimer's disease, both in a test tube and in nematode worms. When the drug was given to worms genetically programmed to develop Alzheimer's disease, it had no effect once symptoms had already appeared.
But when the drug was given before any symptoms became apparent, no evidence of the condition appeared.
The drug works by preventing a process called "primary nucleation" which occurs when proteins in the body misfold and begin to clump together, eventually forming the sticky plaques that cause dementia. "The body has a variety of natural defences to protect itself against neurodegeneration, but as we age, these defences
become progressively impaired and can get overwhelmed," said Prof Michele Vendruscolo of Cambridge's Department of Chemistry, the paper's senior author.
"By understanding how these natural defences work, we might be able to support them by designing drugs that behave in similar ways.
"This, in terms of an approach for Alzheimer's disease, would be the equivalent of what statins do for heart conditions. So you would take them well in advance of developing the condition to reduce your risk.
"I think the spirit should be similar to the way statins are used, so they are given to people that are more at risk of disease and given fairly early.
"There is some evidence that amyloid-beta aggregation takes place in middle age, so we may start in people in their 30s."
The research was published in Science.