Revolutionary blood test to detect signs of Alzheimer's

British scientists say they are close to developing a blood test to spot the early signs of Alzheimer's disease.

A team from King's College in London have identified a series of proteins they say are present in the blood of those at highest risk of developing the neurological condition.

It means patients who test positive for the proteins could amend their diet and take more exercise to stave off their chances of developing Alzheimer's.

Studies have shown those who eat diets rich in omega-3 fish oils and green vegetables are less likely to get dementia.

An estimated 700,000 people in the UK have dementia, and more than half of these have Alzheimer's.

The annual cost to the economy of the condition has been put at £17billion.

Experts believe that delaying the onset of dementia by five years could save 30,000 lives annually.

But the blood test is still to be put through rigorous trials and it would not be available in GP surgeries for five to ten years.

Dr Madhav Thambisetty, researcher at the Institute of Psychiatry at King's College, said: "The challenge has been to find what may cause Alzheimer's and to see if we can identify it before it sets in and therefore give patients an opportunity to have effective treatment.

"Our holy grail is to devise a simple blood test that can eventually be administered at a GP's surgery.

"We feel we are very close to that although we have to be cautious because the research needs more testing. It may be a few years before we have a test, but we are the closest we've ever been."

The optimism follows a study by the team last year which compared protein levels in the blood of 500 Alzheimer's sufferers with those of healthy older people.

They were able to identify which proteins were present in higher quantities in those with Alzheimer's.

A blood test would be an improvement on the current memory test undertaken by GPs, which is very upsetting for patients, takes up to a year for a diagnosis and only spots the disease once its symptoms have set in.

More drugs are being developed to stave off the symptoms of Alzheimer's and sufferers diagnosed before the disease sets in would be able to start on this medication at an earlier stage.

Research director Professor Simon Lovestone said a test would speed up the development of new drugs.

"There are hundreds of drugs in development but the costs, even for large pharmaceutical companies, are immense and almost prohibitive." he said.

"A year's clinical trial can cost £12million as large numbers of patients are needed to get accurate results.

"This research could revolutionise practice because a blood test that accurately monitors progression can reduce the numbers of patients needed for clinical trials."

Professor Clive Ballard, director of research for the Alzheimer's Society, said: "A non-invasive blood test for diagnosing Alzheimer's disease would be of enormous significance.

"Early diagnosis allows people with dementia and their carers to start preparing for their future."

Last week the National Audit Office said the Health Service could save millions of pounds a year by diagnosing Alzheimer's earlier.