Thining of the cerebral cortex, which can happen a decade or more before any symptoms of the debilitating disease, shows up in magnetic resonance scanning.This means more can be done to halt the progress of the disease because it has been spotted at an earlier stage when less damage has occured to the brain.

Current statistics reveal that One in three over-65s will die with dementia.And although there are no clinical tests available for early stage detection, brain shrinkage might indicate early changes in the brain and predict who might get the disease.

US researchers behind the new study say magnetic resonance (MR) scanning is not yet ready to use in diagnosing Alzheimer’s, but the findings bring the prospect closer.

Although existing drugs can slow progression of Alzheimer’s, there is no cure. For the study, researchers used MR scans in people in their 70s with no signs of Alzheimer’s.

They found the risk of developing  the illness was three times greater in those with the thinnest areas of the cerebral cortex area, which plays a key role in memory, compared with those who had above-average thickness. Those with most thinning of the brain also succumbed to the disease faster than people with average thickness, says a report in the medical journal Neurology.