Doctors could one day have a blood test at their disposal that allows them to predict which patients may be at risk of developing Alzheimer's disease, researchers have said.
A team of international scientists led by King's College London and British firm Proteome Sciences carried out examinations of the blood of 452 healthy people, 220 with mild cognitive impairment and 476 with Alzheimer's disease.
Using ten proteins as biomarkers, they were able to tell with an accuracy level of 87 per cent which of those with mild impairment would go on to show signs on Alzheimer's within a year.
At present, the development of drugs to treat the degenerative disease has continued to stall because trials are carried out on people who are already showing symptoms. Since this can happen up to ten years after the onset of Alzheimer's, many of these patients have already experienced too much damage to the structure of their brains.
Scientists therefore want to treat people much earlier - but they need a prediction test to do so and it is hoped this new discovery will provide the missing link.
'We want to be able to identify people to enter clinical trials earlier than they currently do and that's really what we've been aiming at,' lead researcher Professor Simon Lovestone from the University of Oxford told BBC News.
The research is published this month in the journal Alzheimer's & Dementia and further studies will now be carried out to improve trials for potential new dementia drugs.
However, it will take several years and much larger trials before the team can be sure the blood test is safe for widespread use. The next studies will look into boosting accuracy still further, as well as reducing the possibility of misdiagnosis and addressing the issue of depression among people who have been told they may develop the disease.
Nevertheless, Alzheimer's Research UK called the breakthrough a 'technical tour de force'.
It comes just a few weeks after prime minister David Cameron called dementia one of the 'greatest enemies of humanity' and urged researchers and healthcare experts to get behind a 'big push' aimed at beating it within the next few years.